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HISTORY notes for AMPS Python Client

This page provides a list of changes made in each version of AMPS Python Client.

Python version 5.3​

Version 5.3.5.0 (2025-08-04)​

Breaking changes:

  • Client.setDisconnectHandler has been marked as deprecated. Automatic failover should be handled using an HAClient. Monitoring the connection state should be done with a ConnectionStateListener. This change means that the client now enforces the long-standing best practice that applications should not replace the disconnect handler. (AC-1276)
  • Calling setDisconnectHandler on an HAClient will throw a UsageException as this would disable the automatic failover behavior. This change means that the client now enforces the long-standing best practice that applications should not replace the disconnect handler. (AC-1276)

New features:

  • The new bookmark_not_found option available in AMPS server 5.3.5.0 and above is now supported in the Message.Options class. (AC-1338)

Fixes and other changes:

  • Passing AMPS_DEFAULT_TOP_N to Command.setTopN will now correctly unset any topN value and not send a very large number. (z13291) (AC-1129)
  • A ConflatingRecoveryPointAdapter constructed with a SOWRecoveryPointAdapter will now properly increment the reference count on the SOWRecoveryPointAdapter. Previously, the SOWRecoveryPointAdapter could get garbage collected by the Python interpreter leading to a core dump during the next update. (AC-1290)
  • A SOWRecoveryPointAdapter created with a client that hasn't been connected will no longer throw an exception during stack unwind caused by throwing an exception when used to initialize a BookmarkStore. (z18948) (AC-1355)
  • A newly constructed MemoryPublishStore will now always start sequencing at a manufactured value rather than a value based on what the AMPS server acknowledges during logon. This prevents incorrectly treating messages as duplicates in the case where a client has previously published more messages than the AMPS server can acknowledge during logon. (AC-1358)
  • A timeout set on calls to sowDelete, sowDeleteByKeys, or sowDeleteByData functions that return a Message now applies to both the time it takes to get a processed ack from the server and the time the server takes after the processed ack to return the stats ack. (AC-1371)
  • Changed tcps code to use poll instead of select to avoid FD_SETSIZE limit on fd. (z19441) (AC-1373)
  • Prevent a deadlock that could occur from an immediate call to connect on a Client following an exception from calling logon. (AC-1376)

Version 5.3.4.5 (2025-01-15)​

New features:

  • Added http_preflight URI parameter to help route connections to AMPS through proxy servers by starting the connection with an HTTP GET upgrade request. Using this feature requires using the amps protocol and AMPS server version 5.3.4.0 or higher. Extra headers may be set on the GET message using add_http_preflight_header or add_http_preflight_header_key_value multiple times. (AC-1284)

Fixes and other changes:

  • When executing a Command for unsubscribe, the client will now correctly remove any message handlers for the subscription and update the SubscriptionManager to not restart the subscription. (z18760) (AC-1349)
  • Failures when creating a tcps connection using Python3 are now correctly passed along in the AMPSException. (z18174) (AC-1347)

Version 5.3.4.4 (2024-12-18)​

New features:

  • MemoryPublishStore, PublishStore, and HybridPublishStore now have all of the functions found in other languages. New methods are store(Message), discardUpTo(Int), replay(MessageHandler), replaySingle(MessagHandler, Int), getLastPersisted(), and getLowestUnpersisted(). (z18686) (AC-375)
  • For Python 3.X, AMPS.ssl_init() has keyword arguments: dllpath, ssl_context, and strict_ciphers_only. The first arg has always been there. The ssl_context can be an ssl.SSLContext that has already been set up in your Python code. The bool strict_ciphers_only will set Python 3.10+ to use DEFAULT ciphers if False. (z18174) (AC-1322)
  • AMPS.ssl_get_context() can be called after AMPS.ssl_init() to get the underlying ssl.SSLContext. (z18174) (AC-1322)
  • AMPS.Client now has a method get_ssl() that returns the ssl.SSLSocket of a connected client using tcps. (z18174) (AC-1322)

Fixes and other changes:

  • Client source code should now work with versions up to Python 3.13. (AC-1324)
  • Updated HAClient reconnect logic to ensure that a disconnect immediately after successful logon completion can't be missed and leave a client in a disconnected state. Also, added extra protection to keep only a single thread handling reconnect. (AC-1327)
  • Allow DisconnectedException to be thrown by execute for publish and delta_publish commands. (AC-1328)
  • Fixed logic for functions that send a command and don't return until after a processed ack has returned from the server to guarantee that they don't report a DisconnectedException if the disconnect happens before the command has been sent. This can result in seeing a SubidInUseException if the same command is tried again after the DisconnectedException. (z18574) (AC-1329)
  • Fixed logic for functions that return MessageStream objects so they aren't closed if the disconnect occurs before the command is sent. (AC-1331)
  • Fixed logic for commands waiting for a processed ack from the server to ensure that a disconnect only results in DisconnectedException and not a TimedOutException. (AC-1337)
  • The amps protocol parser now correctly parses and serializes headers containing characters that must be escaped in JSON. (AC-1342)
  • SOWRecoveryPointAdapter properly obeys the updateFailureThrows_ flag to throw exceptions in all cases where there is one. (z18648) (AC-1343)
  • BookmarkStore implementations will no longer allow an invalid bookmark used when placing a bookmark subscription to be saved in the store or used when creating the most recent bookmark. Previously, this could lead to always getting an InvalidBookmarkException or in some cases, a core dump while building the most recent bookmark. (z18574) (AC-1345)

Version 5.3.4.3 (2024-08-27)​

Fixes and other changes:

  • Ensured behavior of an exception in ServerChooser.reportSuccess is to call ServerChooser.reportFailure with the exception thrown. (z17400) (AC-1312)
  • Further work ensuring all client receive threads are properly joined or detached, fixing some code paths that were missed in AC-1300. Other cleanup related to valgrind warnings of memory still accessible at application shutdown. (z17180) (AC-1313)
  • Don't request the completed ack automatically for sow_and_subscribe or sow_and_delta_subscribe commands. (z18075) (AC-1314)
  • Always use synchronous send with processed ack when executing Command for commands that return data. (z18075) (AC-1315)

Version 5.3.4.2 (2024-07-15)​

Fixes and other changes:

  • Ensure that all client receive threads are properly joined or detached after a disconnect to prevent memory growth. (z17180) (AC-1300)
  • Prevent an exeption that previously occured from: setting a transport filter on a client, setting the transport filter back to None, then setting a new transport filter on the client. (z16734) (AC-1279)
  • All subscribe and sow commands now send an unsubscribe if they timeout waiting for a processed ack. This avoids having results sent to client later, when the command completes. (AC-1281)
  • Client will no longer automatically request a processed ack on commands that don't return data when used with execute. (z16384) (AC-1283)
  • A UsageException will be thrown from a SOWRecoverPointAdapter if the client passed as the adapter client has the same name as the client it's tracking. (AC-1285)
  • Fix possible deadlock when using a ConflatingRecoveryPointAdapter with a DynamicRecoveryPoint that could occur if the bookmark store attempted to update the adapter while it was doing a conflation update. (AC-1288)
  • Fix escaping of options and orderby fields when using the amps protocol to connect. (AC-1292)
  • Fix MessageStream timeout behavior to match the set timeout rather than be 1 second. (z17169) (AC-1296)
  • Correctly handle timeouts on tcps socket reads to run idle actions like sending batched queue acks and checking for heartbeats. (z17218) (AC-1303)
  • Continue to attempt to send heartbeats on every beat interval rather than simply waiting for read timeout to be exceeded. This may catch disconnects sooner in cases where the server didn't properly close the connection, such as a cloud host shutting down. (AC-1305)
  • The per thread Message used for messages going into a Store is now cleaned up as each thread exits, rather than all at exit. (AC-1306)
  • Ensure that tcps clients handle send failures caused by push back on the socket and properly retry. (AC-1307)
  • Prevent rare deadlock during shutdown caused by calling Python library functions during interpreter finalization. (AC-1311)

Version 5.3.4.1 (2023-12-27)​

New features:

Version 5.3.4.0 (2023-10-09)​

New features:

  • AMPS Python Client now defaults to enabling tcp_keepalive on connections to the AMPS server, consistent with other client languages. Previous behavior can be obtained by adding tcp_keepalive=false to the connect string options. (AC-1256)
  • AMPS Python Client now supports MacOS on arm64 and x86_64. (AC-1200)
  • AMPS Python Client now supports Linux on arm64.
  • Added a way for clients to be notified and take action when a subscription fails after a fail-over event. The HAClient now has a set_failed_resubscribe_handler which takes a callable handling the subscribe message, the requested ack types, and the exception thrown when trying to send the command. The handler should return True to remove the subscription from the client and False to force the client to retry it, including doing a reconnect. (AC-1096) (z12909)
  • Added an optional argument to Client.set_transport_filter to specify if the transport filter might be used to modify the bytes, such as for testing bad data. (AC-1170)
  • Added setErrorOnPublishGap to the Store interface and to Client. If this is set, a Store implementation will throw an exception if a server attempts to acknowledge a sequence number for a message that is already discarded. This can be useful to keep a client from failing over to a server that was not using sync acknowledgement to the server the client was previously connected to until all messages the client published have arrived at the new server. (AC-1202) (z13761)
  • Allow setting a TLS server name indication (SNI) via a connection parameter. (AC-1235)
  • Added get_name_hash_value to Client to return the client's hash id as a number as opposed to the string returned from get_name_hash. (AC-1169)

Fixes and other changes:

  • Ack timeout can't be set to 0 if ack batch size > 1. (AC-1206)
  • Fork handling was added to prevent a child process from starting with a mutex already locked. (AC-1225)
  • Fixed a deadlock in tcps involving 3 threads that could occur when one thread is trying to close the connection during a reconnect event in the receive thread. (AC-1238)
  • Cleaned up some compiler warnings using c++14, c++17, and c++20 as the chosen standard. (AC-1239)
  • Fixed issue with connecting to a server on loopback when there is no outside network connection such as when in airplane mode. (AC-1249)
  • Prevent receive thread from possibly running beyond the lifetime of its Client, possibly causing segv or unexpected behaviors. (AC-1250)
  • Fix sow_and_delta_subscribe convenience function to not send the command twice. (AC-1259) (z16250)
  • Fix a memory leak of a struct addrinfo when trying to bind the client connection to local address fails. (AC-1260)
  • Correct all of Message.Command.xxxEnum values. (AC-1261)
  • Prevent any commands from being sent to the server while waiting for the logon ack and ensure no duplication with commands that are part of the overall logon process such as heartbeat commands. (AC-1262)

Version 5.3.3.5 (2023-05-23)​

Fixes and other changes:

  • Prevent possible crash during interpreter shutdown while clients are still connected and possibly receiving messages. (AC-1195)
  • Client no longer tries to send an unsubscribe command as part of disconnect. (AC-1199)
  • Prevent possible crash during changes to the exception listener, including during shutdown, caused by either not having the GIL or trying to access the GIL during interpreter shutdown. (AC-1210)
  • Prevent possible crash during disconnect handling where a race condition could cause a NULL pointer to be sent to a handler instead of a pointer to the Client. (AC-1211)
  • Change field escaping to include command id and query id but not the correlation id which must be base64 characters. (AC-1215)
  • Optimize logon and flush commands to not use Nagle to avoid a delay in send. (AC-1231)
  • Prevent possible crash if a thread is canceled while attempting to check if the interpreter has been signaled to shutdown. (AC-1236)

Version 5.3.3.4 (2023-01-11)​

Fixes and other changes:

  • Client can now be built with all functions exported on Windows by defining AMPS_SHARED before building. (AC-1204)
  • Removed all calls to pthread_yield and replaced them with wait/signal pairs. (AC-1208)

Version 5.3.3.3 (2021-07-18)​

Fixes and other changes:

  • Break up sleeps from ReconnectDelayStrategy into 1s or smaller chunks to maintain responsiveness to signals. (z13237) (AC-1125)
  • Prevent possible crash from adding Python message handlers to internal tracking when a client is in the process of being destroyed. This could occur if an exception is thrown leading to client destruction right after a new handler has been added to the client as the tracking is handled by the client receive thread. (AC-1141)
  • Fix build issues on Windows with Python 3.10. (z13839) (AC-1159)
  • Prevent possible crash from a Python exception listener being invoked by the client receive thread while the Python client is in the process of being destroyed. (AC-1164)
  • Improved handling and clarity of SSL errors. (AC-1175)
  • Expose heartbeat, timeout_interval, version, and order_by fields on Message. (AC-1181, AC-1190)
  • Fix RecoveryPoint class to avoid crashes from double-free and to ensure correct return values rather than None. (AC-1192)
  • Fix RecoveryPoint __copy__ to avoid crashes. (AC-1193)
  • Fix compilation warnings related to WSAPROTOCOL_INFOA and calls to the select function using Linux-style first argument. (AC-1194)

Version 5.3.3.2 (2021-10-12)​

Fixes and other changes:

  • Fix MemorySubscriptionManager handling of MessageHandler's for subscriptions that are paused and resumed that could lead to a core dump. (AC-1115)
  • Fix compilation warnings on 64bit Windows related to formatting size_t using %lx and forcing conversion to bool. (z13341) (AC-1133)
  • Fix exception translation from server reason strings for reasons starting with "n", such as "not entitled" and "not supported". (AC-1134)

Version 5.3.3.1 (2021-09-08)​

Fixes and other changes:

  • Fix deadlock in HAClient if a disconnect happens while the client is executing a sow_delete, sow_delete_by_keys, or sow_delete_by_data using the asynchronous message processing interface with no message handler provided. (AC-1120) (z13051)

Version 5.3.3.0 (2021-07-20)​

New features:

  • This release supports IPv6 addresses for AMPS servers. (AC-991)
  • New Exception classes have been added to provide more precise exception translation for status codes returned from current versions of the AMPS server. (AC-502)
  • Client::publishFlush now takes an optional argument for the ack type to request. A processed ack matches previous behavior. A persisted ack is a new feature that will ensure all previously published messages are safely persisted by the server. (AC-1046)

Fixes and other changes:

  • A rare double-free could occur when a client's background thread was canceled after it had already begun to free resoures for exit. (AC-1081)
  • An incorrect assert during MessageHandler garbage collection has been removed. (AC-1091)

Version 5.3.2.1 (2021-03-15)​

New features:

  • The Client's name hash used by the server is now available after logon with the get_name_hash() member function. (AC-905)

Fixes and other changes:

  • Client now releases references to MessageHandlers when they are unsubscribed so they can be garbage collected. (AC-456)
  • Client.execute now properly handles subscriptions with the replace option, leaving the current MessageStream as handler for the data instead of creating a new one. (AC-893)
  • Catch exceptions in FailedWriteHandler or global command type message handlers and report them to the ExceptionListener if set. Previously, an exception in one of these handlers could shutdown the background receive thread and cause the client to not receive any more messages from the server. (AC-962)
  • Mask SIGPIPE on Linux to prevent crashes in clients using TLS/SSL. (AC-996)
  • Fix BookmarkStore implementations to honor persisted acks when resubscribing with a bookmark range. (AC-997)
  • Fix memory leak when calling the synchronous form of sow_delete. (AC-1004)
  • Fix race conditions in TCPS implementation that could lead to deadlocks or crashes when attempting to reconnect. (AC-1005) (AC-1025)
  • Fix possible deadlock when one thread calls publish_flush while other threads are calling publish. (AC-1009)
  • Fix race condition in HAClient where one thread could send a command to the server between another thread's calls to connect and logon during a reconnect attempt. The extra command would force an attempt at implicit logon and a likely disconnect forcing another reconnect. (AC-1015)
  • The delta_publish function now returns the sequence number of the published message or 0 if none was assigned. This is the same behavior as publish. (AC-1016)
  • Prevent a race condition while accessing the ReconnectDelayStrategy in HAClient. (AC-1017)
  • Prevent ExceptionListener from being called after it is deleted. (AC-1020)
  • Ids that are automatically generated by the Client are now prefixed with "auto" to prevent unintentional clashes with user-specified, numeric ids. (AC-1027)
  • Prevent deadlocks during destruction of python objects by making sure to release the GIL when calling into C++ code that may acquire locks. (AC-1028)
  • The URI option bind is now error-checked when applied to tcp sockets. It is a synonym for path on unix domain sockets. (AC-1029) (AC-1055)
  • Calls to HAClient.connect_and_logon will reset the ReconnectDelayStrategy before beginning an attempt to connect and logon. Previously, a client disconnected by the delay strategy reaching its maximum timeout value would be unable to connect_and_logon without an explicit call to reset on the delay strategy. (AC-1030) (z12123)
  • When unsubscribe is called, the associated MessageHandler will be released within 1 second rather than the next time a message arrives from the server. (AC-1033) (z12228)
  • Improved hash function is now used in MessageRouter to prevent possible collisions on the hash values of subscription ids. (AC-1034) (z12123)
  • Prevent hang in SSL/TLS clients when using a server with OpenSSL 1.1.1i or newer. (AC-1043)
  • Don't lock the Client when getting members that shouldn't change while connected: BookmarkStore, PublishStore, SubscriptionManager, URI, and FailedWriteHandler. (AC-1053) (z12446)
  • Fix issue in bookmark stores where they could incorrectly return EPOCH as the most recent bookmark in rare cases where the last discarded bookmark and the last persisted bookmark share the same publisher id. (AC-1198)

Version 5.3.2.0 (2020-09-21)​

Breaking changes:

  • The startTimer and stopTimer functions on Client are marked as deprecated. Starting in AMPS server version 5.3.2.0 these commands are no longer available. (AC-969)

New features:

  • The Client now has a setGlobalCommandTypeMessageHandler function that is used to put in place handlers for all messages of a specific command type, such as ack. A MessageHandler put in place this way will get invoked for every message of the given type, regardless of if it is also handled elsewhere. (z3407) (AC-450) (AC-565) (AC-658) (AC-675)
  • Added amps_client_set_thread_creeated_callback the C library and setThreadCreatedCallback to the C++ Client. This will cause the provided function to be invoked every time a new thread is created by the AMPS client library in reposnse to a successful connection. The calling thread is is the new thread and its handle is provided to the callback. (z9855) (z9764) (AC-516) (AC-907)
  • A MemoryBookmarkStore can now be created with a RecoveryPointAdapter. The adapter can be implemented to save a RecoveryPoint somewhere for later recovery to guarantee no missed messages. (AC-527)
  • A SOWRecoveryPointAdapter implementation of the RecoveryPointAdapter interface have been added. The behavior is to save every update into a SOW topic in the server using a separate client. (AC-756)
  • A ConflatingRecoveryPointAdapter implementation of the RecoveryPointAdapter interface have been added. The adapter starts a thread that conflates updates before passing them to an underlying RecoveryPointAdapter such as a SOWRecoveryPointAdapter to reduce the number of updates. (AC-965)
  • Added setAckType to Command class that will clear the current ack type and use the new type, including Message.AckType.None. (AC-886)
  • Added an optional flag to the constructor of the file-based bookmark store classes to tell them to include the file's last modification time in the most recent bookmark until new, usable bookmarks have been added. This is useful in the case where the bookmarks in the file may be older than the bookmarks in the current transaction log to prevent getting NOW behavior if no bookmarks are found. (z5314) (z9621) (AC-887)
  • Added getQueryId and setQueryId to Command class. (AC-927)
  • Added getSequence and setSequence to Command class. The sequence can be checked after a call to execute for commands such as publish, delta_publish, and sow_delete to get the sequence numer that was assigned by the publish store if one was present. (z11000) (AC-954)
  • The bookmark range subscription feature, released in AMPS server version 5.3.2.0, is fully supported by all BookmarkStore implementations to support resumable bookmark range subscriptions. (AC-908)
  • Added get_resubscription_timeout and set_resubscription_timeout to the HAClient class to get/set the timeout used by the subscription manager after a reconnect event when resubscribing. The setting is in milliseconds and a 0 value means that there is no timeout. (AC-820)
  • The append method on FIXBuilder and NVFIXBuilder now returns the builder object so it can be called repeatedly in a single line. (AC-729)

Fixes and other changes:

  • Fix LoggedBookmarkStore to throw an exception if corruption is detected during recovery a file and it does not appear to be the final entry in the file. This is done on a best effort basis using the constants AMPS_MAX_BOOKMARK_LEN and AMPS_MAX_SUBID_LEN which are defined in include\Field.hpp. (z9263) (AC-874)
  • Fix calls to FailedWriteHandler to include the sequence number if one was provided on the persisted ack. (AC-884)
  • Fix Client to not send persisted acks for bookmark subscriptions to the BookmarkStore if the subscription is not currently subscribed. Previously, the persisted acks could be delivered and cause missed messages if everything in the store had been dicarded. (z10045) (AC-912)
  • Fix Client to return an empty MessageStream any time a Command will not return any messages or acks. Previously, commands such as sow_delete that did not request a stats ack could hang if you attempted to iterate the returned MessageStream. (AC-964)
  • Destroying a MessageStream that is only going to receive ack messages before they have all arrived can no longer lead to a seg fault. (AC-975)
  • Fix URI parser to handle percent-escape characters in compliance with RFC 3986 and 1738. (z11551) (AC-987)
  • An exception during Client.execute can no longer cause a seg fault when the same subId or command id is used in another command. (z11017) (AC-983)
  • Calling set_transport_filter_function on a Client that is not yet connected will no longer cause a core dump. (AC-968)
  • Fix possible core dumps during process shutdown with active subscriptions using Python version 3.7 and newer. (z11320) (AC-972)
  • Fix build to use the same python binary to build the C library as is used to build the C++ module on Linux. (AC-992)
  • Fix potential deadlock when calling get_unpersisted_count() on a Client during a reconnect. (z11717) (AC-993)

Version 5.3.0.6 (2020-09-03)​

Fixes and other changes:

  • Fix issue where an HAClient using a tcps connection could get disconnected and not automatically reconnect. (z11623) (AC-989)

Version 5.3.0.5 (2020-04-30)​

Fixes and other changes:

  • Fix issue where acks that were not requested by the application could be delivered to the lastChanceMessageHandler, if one is set. The fix for AC-946 in 5.3.0.4, to route more types of ack messages to the handler, exposed this issue. (z11045) (AC-956)

Version 5.3.0.4 (2020-04-20)​

Fixes and other changes:

  • Removed all warnings found using clang-9, g++ 9.2, and -std= flags: c++11, c++14, c++17, and c++2a. (z01836) (z10987) (AC-928) (AC-952)
  • Fixed a possible use after free error that could occur during destruction of a Client that had returned at least one empty MessageStream from a call to execute. (AC-951)

Version 5.3.0.3 (2020-03-04)​

Fixes and other changes:

  • Fixed a memory leak that would occur if a MessageStream had a timeout set and the attempt to get the next Message timed out. (AC-949) (z10724)
  • sow_and_delta_subscribe will now properly throw a TimeoutException if the processed ack is not returned in time. (AC-934)
  • Client now builds correctly with Python 3.8. (AC-942) (z10560)
  • All ack types not handled elsewhere will now properly reach the last chance handler, if set. Previously, only processed and persisted acks were being delivered to the last chance handler. (AC-946)

Version 5.3.0.2 (2019-11-06)​

Fixes and other changes:

  • MessageStreamImpl destruction is now deferred to the receive thread to prevent a race condition between its destruction and its message handler being called. This could result in a situation where no further messages would be processed for the connection. (AC-918) (z10063)
  • FixedReconnectDelayStrategy and ExponentialReconnectDelayStrategyno longer reset the timer used to check for exceeding the maximum retry time when a new URI is tried. The timer will only restart when the first attempt is made after a successful connection (or construction of the delay strategy). (AC-771) (z7165) (z9674) (z9820)
  • A MessageStream object that fails to auto ack a queue message will close in an error state. (AC-897)
  • Disconnecting a client will no longer throw an exception if batched queue acks fail to flush. (AC-920)
  • Acks for queue messages that were saved in an ack batch will not be lost when a client is forced to reconnect. (AC-921)

Version 5.3.0.1 (2019-08-06)​

Fixes and other changes:

  • A socket leak under some reconnect scenarios in the underlying C client has been corrected. (z9708, z9736, z9741) (AC-898)

Version 5.3.0.0 (2019-07-08)​

Breaking changes:

  • Support for AMPS server versions before 4.0.0.0 has been removed from the BookmarkStore classes to improve their performance. (AC-391)

New features:

  • Added Select and Expire to Message.Options. (AC-882)

Python version 5.2​

Version 5.2.4.0 (2019-05-15)​

Breaking changes:

  • The default batch size for all sow queries has been changed to 10. (AC-700)
  • The BlockPublishStore implementation which underlies all publish stores has been changed to reduce the time required to resize. The file format has also changed, but old format files should be recovered correctly and rewritten by the new implementation. The rewritten files will no longer work with earlier client versions. (AC-817)
  • The RingBookmarkStore class is now available in the Python client. (AC-847)
  • The C and C++ code are now built in separate steps on Linux so there are no longer any compilation warnings from flags that only apply to one of those languages. (AC-863)
  • The Windows build system has been updated to use the latest version of Microsoft Visual Studio found in the environment. (z9247) (AC-869)

Fixes and other changes:

  • Clients will no longer double-ack messages from a Queue when auto ack has been enabled and the code is also calling ack for the Message. (AC-489)
  • Clients will now automatically set an ack timeout when an application sets the ack batch size and the ack timeout is set to 0 (never timeout). When the ack timeout is 0, the Client will automatically set a default ack timeout of 1 second when the ack batch size is set. (z5223) (AC-666)
  • Removed a potential hang in HAClient that was caused by trying to flush ack messages during reconnect. (AC-690)
  • A subscription that throws an exception when placed will now be removed from the SubscriptionManager if one is present. (z5943) (AC-709)
  • MessageStream objects returned for non-subscribe commands now properly mark themselves as closed when all expected acks have been returned. (AC-815)
  • The read timeout on a connection can no longer exceed the heartbeat interval if a heartbeat is set. (AC-819)
  • MessageStream objects produced by a Client with auto ack enabled will now ack the messages after the next message is requested. Previously, acks were sent as soon as messages were saved in the MessageStream which could lead to unprocessed messages being acked if a client processs exited with messages still held in the MessageStream. It could also completely drain a message queue since messages were being acked immediately upon arrival. (AC-825)
  • LoggedBookmarkStore.prune now cleans up files that have only accumulated new persisted bookmarks. Previously, only a change in the last discarded bookmark would cause prune to modify the file. (z8434) (AC-831)
  • Fork handling has been implemented to prevent deadlocks when using multi- processing. (AC-832)
  • LoggedBookmarkStore.prune will now retry file delete and rename operations in case of slow file system updates. (z7614) (AC-836)
  • Added AMPS.ssl_set_verify and AMPS.ssl_load_verify_locations functions to enable certificate verification. (AC-839)
  • Removed potential hang in HAClient if an exception was thrown during logon and the background thread was attempting to flush queue acks. (AC-840)
  • Fixed possible hang or missed acks when a disconnect occurred while sending sow_delete commands. (z8567) (AC-841)
  • Fixed incorrect parsing of amps protocol messages containing a topic with a trailing / character. (z8648) (AC-843)
  • Fixed sow_and_subscribe to no longer set top_n on all queries. This bug first appeared in version 5.2.3.0. (AC-845)
  • Fixed BlockPublishStore to always restore _resizing to false and prevent a hang if there is an exception while attempting to grow. (z8769) (AC-853)

Version 5.2.3.0 (2018-09-14)​

New features:

  • The Client.logon function can now be called with an options string, such as "ack_conflation=500ms" (AC-792).
  • The HAClient class now has setLogonOptions and getLogonOptions functions to set the options to be used for logon each time it's called (AC-792).
  • The VersionInfo class has been introduced to provide an encapsulated way to represent and compare server versions. Client.get_server_version_info() returns the new type (z7665) (AC-789).
  • OpenSSL version 1.1.0 and higher can now be detected and used for tcps connections. (AC-800)
  • Added Client.set_transport_filter() to provide a cross-transport way of adding a filter function. (AC-803)
  • Added Message.get_data_raw() to provide access to data on a message as bytes rather than a string when using Python 3. In Python 2, bytes are returned by both get_data() and get_data_raw(). (AC-793)

Fixes and other changes:

  • Error messages from a failure in getaddrinfo() are now properly thrown by the Client (z7935) (AC-801)
  • The Client.ack(topic, bookmark) function no longer erroneously places the bookmark in the options field causing the ack to fail (z7882) (AC-802).
  • The ampspy_types.hpp header no longer depends on the client itself providing an implementation of any Py* functions. The client provides these functions when building with a version of Python that does not provide a given function. This is a common approach to Python version compatibility: this change was made to avoid conflicting with definitions in customer applications that are designed to work with both Python 2 and Python 3. (z7924) (AC-809).

Version 5.2.2.2 (2018-07-06)​

Fixes and other changes:

  • Fix issue with gcc 5.2 and address sanitizer where a cast from Client& to HAClient& during disconnect handling would cause address sanitizer to report an error. More recent versions of gcc were not affected. (AC-788) (z7645)
  • Fix race condition with functions returning MessageStream where the subscribe family of calls could potentially not send the subscribe command to the server during a reconnect, so the MessageStream would always be empty. (AC-787) (z7622)
  • Fix potential deadlock between the python GIL and the Client lock when using both MessageStream and a ConnectionStateListener. (AC-790) (z7676)

Version 5.2.2.1 (2018-06-12)​

Fixes and other changes:

  • Fix Client.unsubscribe(id_) to properly throw DisconnectedException if the Client is disconnected when calling the function. Previously, this could hang. (AC-772)
  • Fix Client to only add MessageHandlers for new identifiers (command, subscription, or query). (AC-773)
  • Fix compilation errors when using Microsoft Visual Studio 2010. This compiler version has not been covered by Microsoft mainstream support since 2015, and will not be supported after this release. (AC-779) (z6468)

Version 5.2.2.0 (2018-04-04)​

Breaking changes:

  • The ConnectionStateListener class has been expanded to include: LoggedOn, HeartbeatInitiated, PublishReplayed, Resubscribed, and Shutdown states. Shutdown indicates that the Client has been disconnected and is not going to try to reconnect itself. A client shouldn't be used to execute AMPS server commands until after a listener has received either the LoggedOn state for a Client or the Resubscribed state for an HAClient. Note: enum value order and associated int values have also changed. (AC-457) (z3494, z6468)

New features:

  • Added a second, optional argument to Client.add_connection_state_listener to specify the version of your listener. Client.ConnectionStateListener.EXTENDED_STATES indicates it expects the int values above. The default, or any version less than that such as Client.ConnectionStateListener.ORIGINAL_VERSION indicates it expects only True or False for connected or disconnected (includes SHUTDOWN).
  • Added Client.set_default_max_depth, Client.get_default_max_depth, MessageStream.get_max_depth, and MessageStream.get_depth methods to control the max depth on new MessageStream objects created by the Client and to monitor the depth on the MessageStream. (AC-680) (z5557)
  • Added ability to bind outgoing connections to a server to a specific local address or port using ?bind=addr[:port] in the URI. (AC-701) (z6000)
  • Added an optional string argument to Client.ack and Message.ack methods to allow passing of an options string, such as "cancel". (AC-726)
  • Removed possible memory leak of a MessageStream when an exception is thrown by Client.execute. (AC-751)
  • Added ability to use pretty printing of binary message types as the data format by specifying ?pretty=true in the URI. (AC-755)
  • Fixed possible core dump if HAClient was destroyed while a thread was still trying to reconnect. (AC-761)
  • Added missing Message.is_records_updated_null method. (AC-669)(z5530)

Fixes and other changes:

  • Fix Client.unsubscribe to properly throw DisconnectedException if the Client is disconnected when calling the function. Previously, this could hang. (AC-760) (z6892)
  • Fix Client.unsubscribe to properly remove all MessageHandlers in place for subscriptions. (AC-768)
  • Fix a possible deadlock in HAClient that could occur if logon fails while trying to connectAndLogon. (AC-769) (z7057) (z7103)

Version 5.2.1.6 (2018-01-11)​

Fixes and other changes:

  • Fixed memory leak when command execution results in an exception. (AC-715)
  • Fixed race condition which could result in a deadlock during disconnect handling. (AC-750)

Version 5.2.1.5 (2018-01-03)​

Fixes and other changes:

  • BlockPublishStore.store() now properly reclaims memory used and prevents the partial Message from being replayed. (AC-734)
  • The Client.convertVersionToNumber() function, used by Client.getServerVersion(), now treats any portion of a version that is larger than 99 as 99. (AC-730)
  • Fix race condition in the MessageRouter class that could cause improper message routing or even a crash. (Z6536) (AC-748)
  • Remove a compiler warning in mmapbookmarkstore.cpp introduced in version 5.2.1.4. (Z6503) (AC-746)
  • The HAClient disconnect handling could incorrectly stop retrying to connect when failing to connect multiple times. (Z6468) (AC-749)

Version 5.2.1.4 (2017-12-15)​

Fixes and other changes:

  • Message queue cancel acks are now properly stored with the cancel option in all store classes, and will not be replayed during a reconnect event to prevent an incorrect cancel of a message. (AC-732)

  • Messages that do not contain a bookmark will no longer create an invalid sow_delete ack message if the ack() method is called. (AC-733)

  • Clients that had called set_ack_timeout() could hang and consume 100% cpu if the server connection was lost. (Z6472) (AC-741)

  • Methods to access and set the MessageType, RecordsInserted, and RecordsUpdated fields were added to the Message class. (AC-669)

Version 5.2.1.3 (2017-11-17)​

Fixes and other changes:

  • An embedded NULL in an amps protocol header field no longer causes the client to disconnect. (AC-694)
  • Fixed a number of issues when using a Store on a Client that is consuming from an AMPS Queue. Issues included incorrect unpersisted count, incorrect duplicate detection, hangs while trying to flush the Store, and large memory growth of the Store. (AC-707) (AC-708) (AC-711) (AC-712)
  • Updated exception messages to include the method name when there is an error setting a Field on a Message. (AC-714)
  • Fixed calls to sowDelete* functions to remove the MessageHandler if a timeout occurs. (AC-717)
  • Fixed MemorySubscriptionManager to prevent subscriptions from being deleted while they are being resubscribed. (AC-717)

Version 5.2.1.2 (2017-09-27)​

Fixes and other changes:

  • Improved performance of recovery of the file-based bookmark store classes: MMapBookmarkStore and LoggedBookmarkStore. (AC-683) (Z5652)
  • Improved prune function for MMapBookmarkStore and LoggedBookmarkStore to only prune the file when the prune will change the size of the file. (AC-684) (Z5652)

Version 5.2.1.1 (2017-05-12)​

New features:

  • The bookmark_delta_subscribe function has been removed from Client as the AMPS server does not support this operation. (AC-646)
  • Added Client.setRetryOnDisconnect method that allows for commands being sent to the server to not retry if they fail the first time. (AC-635)

Fixes and other changes:

  • Fix build warnings and errors on Windows with older compilers. (AC-641) (Z4888)
  • Fix MMapBookmarkStore.prune() to start with the default file size rather than the size of the current store file. (AC-642) (Z4909)
  • Fix recovery of file-based bookmark stores to have a most recent of EPOCH when there were messages logged but no messages discarded. (AC-643)
  • Command object reuse will no longer cause unrequested acks to be delivered to the message handler. (AC-645)

Version 5.2.1.0 (2017-03-08)​

New features:

  • Added support for python3

Fixes and other changes:

  • Fix non-deterministic core dump caused by calling PyCallable_Check without holding the GIL. (AC-615)

Version 5.2.0.0 (2017-02-09)​

New features:

  • Added new options for 5.2.0.0 and newer AMPS servers (AC-584) (AC-605):
    • SkipN
    • Projection
    • Grouping

Fixes and other changes:

  • Fix possible core dump from recursive GC involving Client and MessageHandler objects saved in the Client. (AC-607)

Python version 5.1​

Version 5.1.0.0 (2017-01-31)​

New features:

  • Expose additional methods from MemoryBookmarkStore and MMapBookmarkStore. (AC-471)
    • log
    • discard_message
    • discard
    • get_most_recent
    • is_discarded
    • persisted
    • persisted_index
    • purge
    • get_oldest_bookmark_seq
    • no_persisted_acks
    • set_server_version
  • Added new function setResubscriptionTimeout to MemorySubscriptionManager class to change a non-static value used for timeouts during resubscription. Previously, there was only a single static value. (Z3372) (AC-461)
  • Added new get functions to Client for heartbeat interval and read timeout. (Z3720) (AC-508)
  • Added new options for 5.1.0.0 and newer AMPS servers (AC-532) (AC-543):
    • Conflation
    • ConflationKey
    • FullyDurable
    • RateMaxGap
  • Added new function purge_sub_id to the BookmarkStore implementations. This function will completely remove all records for the given subscription id from the store. (Z4087) (AC-540)
  • Add support for Visual Studio 2015. (AC-470)

Fixes and other changes:

  • Allow Client.setHeartbeat() to be called before connecting. (AC-509)
  • Options no longer have a trailing , when sent to the server. (AC-431)
  • Prevent multiple threads from calling HAClient.connectAndLogon at the same time. (AC-449)
  • The MemorySubscriptionManager.DefaultResubscriptionTimeout has been changed to 0, or no timeout. (Z3372) (AC-460)
  • Updated LoggedBookmarkStore.prune function to be more complete in what is saved in the pruned file. There was a small possibility for duplicate messages being delivered. (AC-479) (AC-523)
  • Differentiate NotEntitledException message between logon and other commands. (AC-511)
  • Fix MemorySubscriptionManager to reset state properly if there is an exception during resubscribe. Previously, it could produce a deadlock. (Z3928) (AC-519)
  • Fix PublishStore so that messages larger than 2048 * _blocksPerRealloc no longer can cause a crash. (AC-512)
  • Fix compilation warning on Windows. (AC-475)
  • Fix protocol error using non-numeric SOW keys. (AC-515)
  • Optimize message delivery when messages are arriving for the same subscription id. (AC-521)
  • Fixed PublishStore to avoid the possibility of possible corruption during a resize while multiple threads are publishing with the same client and the client is forced to reconnect. (AC-534)
  • Fixed Client to prevent simultaneous message processing in a rapid disconnect/connect scenario that could lead to message corruption. (AC-535)
  • Fix threading issues when using tcps transport that could lead to hangs or incorrect data. (AC-558)
  • Fix race condition that could put in place an incorrect MessageHandler for a subscription if MemorySubscriptionManager is doing a resubscribe while another thread is updating the same subscription with a replace, pause, or resume. (AC-559)
  • Fix FixedDelayStrategy so that a maximum of 0 always means retry indefinitely. (AC-561)
  • Fix Client so that a call to get_unpersisted_count does not segfault if no publish store has been set. (AC-536)

Python version 5.0​

Version 5.0.1.2 (2016-08-25)​

Fixes and other changes:

  • Fix issue where an ack would be delivered to the last chance message handler when acking a message from a queue. (Z3513) (AC-472)
  • Fix issue where a long-running python thread could block the Client receive thread after it sends a heartbeat response. (Z3460) (AC-499)
  • Fix bug where a Client with a PublishStore could have its publish messages seen as duplicates by the server if the client was also acking messages from a queue. (Z3609) (AC-490)

Version 5.0.1.1 (2016-06-13)​

This version contains the following additions and fixes:

  • Fix sow_delete_by_data to accept data with embedded nulls. (Z3392)
  • Fix HAClient to retry connecting if reportSuccess on the ServerChooser throws an exception. (Z3256)
  • Fix bug in Client that could cause a LoggedBookmarkStore or MMapBookmarkStore to have an incorrect value for most recent for AMPS servers version 4.0.0.0 and above. (AC-447)
  • Provide the ability to implement BookmarkStore and PublishStore in Python (in addition to C++). Stores implemented in Python can be used with the HAClient.

Version 5.0.1.0 (2016-05-26)​

This version includes the following changes and fixes:

New features:

  • This release adds support for secure socket layer (SSL) encryption of connections to AMPS, supported in 5.0.0.0 and higher versions of the AMPS server. See the developer guide for information on adding SSL support to your applications. See the most current AMPS User Guide and AMPS Configuration Reference for creating a Transport that uses SSL.

Fixes and other changes:

  • Fix bug in LoggedBookmarkStore.prune and MMapBookmarkStore.prune that could result in invalid bookmarks or invalid entries in the store. (Z3165, Z3268) (AC-439)

Version 5.0.0.1 (2016-03-25)​

  • Client properly processes connection options (for example, tcp_nodelay), fixing a bug introduced in 5.0.0.0 that would cause the client to throw an exception in some cases when connection options were present. (Z3119)
  • Client will now respond to authentication challenges with user id sent by the server in its response. (Z2993)
  • BookmarkStore implementations will now return a list of bookmarks as the MOST_RECENT when:
    • The original subscription was for NOW,
    • Some bookmarks have been discarded, and
    • No persisted ack has yet been received from the server. (Z3106)

Version 5.0.0.0 (2016-02-29)​

This version is a major update of the AMPS Python client. It includes feature support for new features in AMPS 5.0.0.0, including:

  • Awareness of message queues, including options to enable automatic acknowledgement of queue messages, set a batch size for automatic acknowledgement, and so forth.
  • Support for pause and resume on bookmark subscriptions. The AMPS Python client is now aware of the pause and resume options for bookmark subscriptions, and stores the state of a bookmark subscription in the SubscriptionManager to re-establish the connection in the correct state when failover occurs.

This version also includes the following fixes and improvements:

  • Update version in underlying C++ client to match version of the python client, so that the version number sent to the AMPS server is meaningful. (AC-370)
  • Fixed NVFIXBuilder and FIXBuilder to stop leaking a python String object when converting appended values from a non-string type (Z2017)
  • Attempting to set a store on a client that is already connected will now throw an AlreadyConnectedException instead of a UsageException. (AC-306)
  • Calling connect on an HAClient will now forward the call to connect_and_logon. (AC-306)
  • Attempting to call logon on an HAClient will throw an Exception stating to use connect_and_logon. (AC-306)
  • DefaultServerChooser now has an add_all function that will take a list of uri strings to be added in order. (AC-361)
  • Client will invoke the FailedWriteHandler for all failures. Previously it was only invoked for duplicate and not entitled failures. (AC-339)
  • Added NoTopic to the Reason class.
  • The version sent to AMPS in logon is now getVersion() + ":python" to aid in debugging. (AC-385)
  • Added add_message_handler and remove_message_handler functions to Client so the non-blocking version of send can be used and results will still be handled. (AC-333)
  • The TransmissionTime field has been renamed to Timestamp.
  • The following deprecated fields have been removed from Message (AC-294):
    • MaximumMessages (max_messages)
    • MessageID (message_id)
    • SendEmpty (send_empties)
    • SendOutOfFocus (send_oof)
    • SendSubscriptionIDs (send_matching_ids)
  • Change all Store implementations to set the initial sequence number to a large value based on current time. This prevents backtracking in sequence numbers when simultaneous server and client failures occur and replication is in use. (Z1986) (AC-384)
  • Change the timeout argument of publish_flush to be a keyword argument rather than just positional. (Z2189)
  • Fix MessageStreams with a timeout set so the MessageStream will end iteration for commands that have a defined end point, such as sow queries. Previously, MessageStreams with a a timeout set would continue to produce invalid messages after receiving the group_end for a sow command or when a stats ack is returned and the ack is the only message expected.
  • Fix Client.set_transport_filter to throw an exception instead of crashing when called on a not-connected client. (Z2217)
  • Changed the send, execute and executeAsync methods on Client to return all acks that are set on the Command object to the MessageStream or MessageHandler. Previously, acks that were used internally in the Client, such as processed acks, were blocked from being returned. (AC-332)
  • Changed failed write handler interface to accept a Message and a reason string. Handlers with the old interface should continue to work in this release.
  • PublishStore will recover up to the first corrupt message, then clear corrupt data before throwing an exception so that the store and its file are recoverable. (AC-404) (Z2458)
  • PublishStore has a new function truncate_on_close(boolean), which, if set to True will cause an empty PublishStore to attempt to truncate its file to initialSize blocks when it is closed. (AC-405) (Z2255)
  • Added Pause, Resume, and Rate() to Message.Options for building Command options strings. (AC-406)
  • Added support for passing a Client to a user-defined C/C++ function through the ctypes interface. (AC-420)

Python version 4.3​

Version 4.3.1.5 (2016-12-18)​

This version contains the following additions and fixes:

  • Fix possible SEGV during garbage collection of Client. (Z2559) (Z2585)

Version 4.3.1.4 (2015-11-18)​

This version contains the following additions and fixes:

  • Restored synchronous behavior of Client.sow_delete_by_keys when no on_message parameter is supplied. In versions 3.8.1.x, calling sow_delete_by_keys with no message handler resulted in synchronous execution followed by the return of the "stats" message from the server. In versions 4.0.0.0 through 4.3.1.3, this same usage resulted in an error. (Z2485)

Version 4.3.1.3 (2015-09-15)​

This version contains the following additions and fixes:

  • Fixed ExponentialDelayStrategy to never exceed the maximum delay, even when using jitter. (Z2190)
  • Fix ExponentialDelayStrategy on Windows to properly retry for the entire maximumRetryTime. (Z2190)

Version 4.3.1.2 (2015-08-20)​

This version contains the following additions and fixes:

  • Fixed NVFIXBuilder and FIXBuilder to no longer leak a python String object when converting appended values from a non-string type. (Z2017)
  • Fix SEGV when an AMPS.Client is deleted by the python garbage collector and that Client has an exception listener registered where the exception listener has a circular reference to the deleted Client. (Z2090)
  • Fix Client to properly process authentication retry acks.

Version 4.3.1.1 (2015-07-22)​

This version contains the following additions and fixes:

  • Prevent possible OOM when a MessageStream is resubscribed after a disconnect and never closed.
  • Fix to make sure that messages reported by AMPS as not entitled are discarded from the client's publish store. (Z1961)
  • Update version in underlying C++ client to match version of the python client, so that the version number sent to the AMPS server is meaningful. (AC-370)
  • Modify SyncSOWDeleteMessageHandler state to be volatile to avoid a possible race condition and add a default timeout (Z1894).
  • Pass exception and traceback object to user-supplied exception listeners. (AC-394)

Version 4.3.1.0 (2015-06-03)​

This version contains the following additions and fixes:

  • Added new classes CompositeMessageBuilder and CompositeMessageParser for working with composite message types.
  • Added new method MessageStream.timeout() to set the timeout when calling the next method, or when iterating over a message stream.
  • Calling set_heartbeat on an HAClient that is not connected will no longer throw a DisconnectedException. (Z1570)
  • Fixed object reference leak when destroying a Client or HAClient object. (Z1613)
  • Added support for garbage collection and cyclic references to Client and HAClient. (Z1627)
  • Added new class FixedDelayStrategy and ExponentialDelayStrategy, along with setter and getter on HAClient. These classes and methods provide custom and advanced sleeping strategies when failing over.
  • Added support for weak references to Client and HAClient. (AC-325, Z1623)
  • Allow None to be passed to set_disconnect_handler, set_last_chance_message_handler, set_duplicate_message_handler, and set_exception_listener, in order to "unset" the handler. (AC-320, Z1609)
  • Added Client.get_exception_listener and Client.get_duplicate_message_handler. (Z1608, AC-319)
  • Removed ServerChooser.next(). (AC-114)
  • Added optional "timeout" parameter to Client.publish_flush (AC-326)
  • Ensure that messages are saved to publish store and sent sequentially when multiple threads are calling publish and sowDelete functions on the same client at the same time. (Z1617) (AC-217)

Python version 4.0​

Version 4.0.0.6 (2015-05-08)​

This version introduces the following new features and fixes:

  • Fixes race condition in Client sow, sow_and_subscribe, sow_delete, and sow_and_delta_subscribe methods where the returned command ID or subscription ID may be incorrect when using a Client from multiple application threads. (Z1700)
  • Fix to make sure that messages reported by AMPS as duplicate or not entitled are discarded from the client's publish store. (Z1640)

Version 4.0.0.5 (2015-04-28)​

This version introduces the following new features and fixes:

  • Fixed fatal error that could occur when a program receives SIGINT (or Ctrl+C is pressed) while an HAClient is attempting to reconnect and the signal causes a user-supplied exception listener to be called. (Z1714)

Version 4.0.0.4 (2015-04-14)​

This version introduces the following new features and fixes:

  • Unhandled exceptions from a user message handler that are thrown in response to a sow, group_begin, or group_end message are now caught and sent to the user-supplied exception listener. (Z1649)
  • Setting an exception listener on a Client no longer causes a crash or hang at exit when a MessageStream object outlives a Client. (Z1656)

Version 4.0.0.2 (2015-03-03)​

This version contains fixes for the following issues:

  • Fixed process hang at Python interpreter exit when using a global HAClient instance on Windows. (Z1541)
  • Fixed compiler warnings when compiling the client library 32-bit on Linux. (Z1528)
  • Correctly set the version string for the Python client on build. (Z1529)

Version 4.0.0.1 (2015-02-20)​

This version contains fixes for the following issues:

  • Fixed race condition that leads to an occasional SEGV when disconnecting a client, or when shutting down while a client is connected. (AC-283)
  • Fixed crash that may occur when a MessageStream is still receiving messages while the calling program exits. (Z1407)
  • Changing the BookmarkStore or PublishStore on a connected client raises a UsageException. (Z1407)
  • Fixed silent failure when calling FIXBuilder.append() with a non-integer key. This failure sometimes results in TypeError being thrown from unrelated parts of your program.

Version 4.0.0.0 (2014-12-08)​

This version of the AMPS Python Client is a major update to the programming interface. It introduces new functionality, and is not fully source compatible with previous versions. See the section on "Updating Applications to 4.0.0.0 in this HISTORY file for information on updating applications.

This release contains the following breaking changes:

  • Renamed set_unhandled_message_handler to set_last_chance_message_handler. (AC-197)
  • Renamed published_duplicate_handler to failed_write_handler. (AC-280)

This version introduces the following new features and fixes:

  • Fixed race condition that leads to an occasional SEGV when disconnecting a client, or when shutting down while a client is connected. (AC-283)
  • Add new Command class to facilitate more flexible and easier execution of AMPS commands, along with execute and execute_async methods on Client to execute a Command.
  • Added the ability for the AMPS Python client to load and use message handlers implemented in C++. See the developer guide and the API reference for details.
  • Include the AMPS Command Reference in the client distribution to provide a guide to using the new Command class.
  • Removed 22-character limit from command, subscription, and query IDs (AC222)
  • Record sow_delete operations in publish stores so that, during replay, sow_delete and publish messages are replayed in the same order they were originally sent. (AC207)
  • Disallow subscriptions with the "replace" option when no subscription ID is passed, to help prevent programming errors with this option. (AC153)
  • Ensure the appropriate subscription ID is used for bookmark logging when multiple subscriptions to the same topic are placed.
  • Add RecordsInserted, RecordsUpdated, and OrderBy fields to Message. (AC106)
  • Add CDATA escaping to topic and filter fields for XML protocol. (AC216)
  • Store and use multiple bookmarks to avoid missing messages when failing over between replication pairs.
  • Increased robustness of publish_flush() method by using new flush command on the AMPS server when available. (AC182)
  • Cause all sow_delete methods to request a stats ack from the server.
  • Added support for orderby, bookmark, and topN arguments to sow, sow_and_subscribe, and sow_and_delta_subscribe.
  • Added optional sub_id parameter to all subscription methods on Client.

Updating Applications to 4.0.0.0

The set_unhandled_message_handler method has been renamed to set_last_chance_message_handler. Replace calls to the function with the new name.

Throughout the client, message_type has been renamed to protocol.

Version 3.8.1.1 (2014-09-19)​

This release of the Python client is compatible with 3.8.1.0

This version contains fixes for the following issues:

  • Client.disconnect() no longer clears the URI for the client. (Z1057, AC-252)
  • Correctly lock the URI for the client when accessing it to protect against concurrent updates. (Z1057, AC-252)
  • Deep copying a Message now correctly copies the bookmark sequence number of the Message. (Z958)

Version 3.8.1.0 (2014-07-29)​

This release of the Python client adds new client-side functionality. The client does not remove any interfaces and is source compatible with previous releases of the client. However, this release of the client does change the format of publish store files.

This version contains fixes for the following issues:

  • Publish stores now store message expiration. This fix includes a change to the file format for file-based publish stores. This version of the client will correctly read files from previous versions of the client. However, previous versions of the client cannot read publish store files created by version 3.8.1.0 and later of the client. (Z880)
  • Applications that use a Store will no longer lose the first published message after recovery. Previously, if the Store had exactly 1 unsent message during recovery, the client would reuse a message sequence number, making the message appear to be a duplicate. (AC200)
  • Clients that use a file based PublishStore no longer lose messages when the application is restarted with unpublished messages. Previously, errors in recovery would cause unpublished messages to be lost. (AC200)
  • Clients that use a PublishStore can no longer incorrectly try to resize to very large sizes after replay. This behavior could cause out of memory errors. (AC200)
  • LoggedBookmarkStore will no longer throw an exception if there is file error after some data has been recovered and will instead stop recovery after the last good record. This prevents abrupt client shutdowns leaving the entire file corrupt rather than just the final record. (AC196)
  • Fix unresponsiveness to Control-C that could occur when trying to connect in HAClient connect_and_logon or when trying to publish while the reader thread is trying to connect in HAClient connect_and_logon(Z895).

This version also adds the following new functionality:

  • Added new synchronous versions of subscribe, sow, sow_and_subscribe, sow_and_delta_subscribe, and sow_delete. The new versions of these methods no longer require a message handler. Instead, these versions of the methods return a MessageStream which can be used for iteration. When there are no more messages available, iteration is complete and the stream is automatically closed. For example, the new version of subscribe can be invoked as:

    for message in client.subscribe("my-sow-topic"):
        print message.get_data()

  • Added new sow_delete_by_data() function. This function takes a topic and a message. AMPS uses the provided message to identify the SOW record to delete. AMPS deletes the record that would be updated by the message provided.

  • Added get_server_version() function to Client to return the version of the connected AMPS server. This function returns a numeric value with the pattern: Major Minor Maintenance Hotfix

    Two digits are available for each part of the version. For example, AMPS server version 3.8.1.5 will return 3080105. This is supported for all versions of AMPS 3.8 and later. If the client is connected to an earlier version of AMPS, this function will return 0. (Z884)

  • Added get_server_version_from_string() function to Client to return the numeric value for a given version string for comparison with values returned by get_server_version(). This function can work with shortened version strings such as "3.8" which will return 3080000.

  • Added VERSION string to AMPS for the client version and fixed version in setup.py to be the current version. (AC-169)

Version 3.8.0.3 (2014-05-06)​

  • Updated API documentation with correct units for timeout. (Z771)
  • Prevent possible deadlock on Windows when two or more threads call a synchronous method on the same client at the same time. (Z763)
  • Enable message handlers on one client to call synchronous methods (like sow(), logon()) on another client. (Z763)

Version 3.8.0.2 (2014-03-11)​

  • Improved thread safety of client. Using the same client object in multiple threads will no longer produce a "Fatal Python error: deallocating None" error.
  • Eliminated the possibility of receiving a "TypeError: an integer is required" error when passing None as an expiration value to publish and delta_publish.

Version 3.8.0.1 (2014-02-24)​

  • The None keyword is now accepted for message expiration for both publish and delta_publish.
  • Publish functions now accept keyword arguments.
  • The expiration field in published messages had an unnecessary trailing NULL byte. This is no longer sent.
  • The send function now ensures that ackType and all necessary IDs are properly set for all types of messages.

Version 3.8.0.0 (2014-02-21)​

  • Change version number so that major/minor version matches server release. There are no AMPS Python client releases versioned 3.3 through 3.7.
  • Include the most recently certified C++ client sources into the Python client package. You no longer need to download a C++ client or set AMPS_CPP_DIR to build the Python client. You can still set AMPS_CPP_DIR if you choose to use a C++ client other than the one included in the Python client package.
  • Change version number so that major/minor version matches server release. There are no AMPS Python client releases versioned 3.3 through 3.7.
  • Improve interface for replacement subscriptions. Add new sub_id optional parameter to various subscribe commands on Client to make it easier to do replace requests and allow them to update the default MemorySubscriptionManager in the HAClient.
  • Protect against unbounded store growth. Add new setResizeHandler functions on the publish and bookmark store classes so clients can take action when a store is growing.
  • Fix bug in reference counting on ServerChooser when using a custom Authenticator, which caused a SEGV when using a new-style class as a custom Authenticator.
  • Cause the "reason" field of the "info" dictionary passed to ServerChooser report_failure() to contain the text of any python exception encountered, instead of "a python exception occured."
  • Fix unresponsiveness to Control-C that could occur when tring to connect in HAClient connect_and_logon.

Version 3.2.0.2 (2013-12-11)​

  • Add new wrappers for PublishStore, MemoryPublishStore, MMapBookmarkStore and MemoryBookmarkStore, HybridPublishStore. Add methods for set_publish_store and set_bookmark_store.
  • Add a new HAClient constructor keyword argument, no_store, to prevent bookmark and/or publish stores from being created in memory.
  • Add support for new C++ client api, Client.publish_flush (publishFlush in C++).
  • Fix for possible crash when multiple clients subscribe within a single application.
  • Update RECENT bookmark to MOST_RECENT to match documentation and other languages.

Version 3.2.0.1 (2013-11-22)​

  • Add new HAClient.connect with a more helpful exception when no argument is passed.
  • Fix SEGV that occurs when an uninitialized HAClient is freed.

Version 3.2.0.0 (2013-11-15)​

Initial release of this implementation.

  • Re-written as a Python extension module atop the AMPS C++ Client, including HAClient functionality.
  • Added sow_delete_by_keys.
  • Added FIXShredder
  • Reorganized Exception hierarchy to make current exceptions inherit from legacy exceptions.