From b15e32a943ae269c1c7dae4b2084e2ad87f3940d Mon Sep 17 00:00:00 2001 From: Alex Rudyy Date: Wed, 15 Apr 2015 10:00:55 +0000 Subject: QPID-6481: Move java broker docbook into java source tree git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1673703 13f79535-47bb-0310-9956-ffa450edef68 --- ...Broker-Runtime-Producer-Transaction-Timeout.xml | 137 --------------------- 1 file changed, 137 deletions(-) delete mode 100644 qpid/doc/book/src/java-broker/Java-Broker-Runtime-Producer-Transaction-Timeout.xml (limited to 'qpid/doc/book/src/java-broker/Java-Broker-Runtime-Producer-Transaction-Timeout.xml') diff --git a/qpid/doc/book/src/java-broker/Java-Broker-Runtime-Producer-Transaction-Timeout.xml b/qpid/doc/book/src/java-broker/Java-Broker-Runtime-Producer-Transaction-Timeout.xml deleted file mode 100644 index 2813274c61..0000000000 --- a/qpid/doc/book/src/java-broker/Java-Broker-Runtime-Producer-Transaction-Timeout.xml +++ /dev/null @@ -1,137 +0,0 @@ - - -%entities; -]> - - -
- Producer Transaction Timeout -
- General Information - The transaction timeout mechanism is used to control broker resources when clients - producing messages using transactional sessions hang or otherwise become unresponsive, or simply - begin a transaction and keep using it without ever calling Session#commit(). - Users can choose to configure an idleWarn or openWarn threshold, after which the identified - transaction should be logged as a WARN level alert as well as (more importantly) an idleClose or - openClose threshold after which the transaction and the connection it applies to will be - closed. - This feature is particularly useful in environments where the owner of the broker does not - have full control over the implementation of clients, such as in a shared services - deployment. - The following section provide more details on this feature and its use. -
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- Purpose - This feature has been introduced to address the scenario where an open transaction on the - broker holds an open transaction on the persistent store. This can have undesirable consequences - if the store does not time out or close long-running transactions, such as with BDB. This can can - result in a rapid increase in disk usage size, bounded only by available space, due to growth of - the transaction log. -
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- Scope - Note that only MessageProducer clients will be affected by a transaction timeout, since store - transaction lifespan on a consumer only spans the execution of the call to Session#commit() and - there is no scope for a long-lived transaction to arise. - It is also important to note that the transaction timeout mechanism is purely a JMS - transaction timeout, and unrelated to any other timeouts in the Qpid client library and will have - no impact on any RDBMS your application may utilise. -
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- Effect - Full details of configuration options are provided in the sections that follow. This section - gives a brief overview of what the Transaction Timeout feature can do. -
- Broker Logging and Connection Close - When the openWarn or idleWarn specified threshold is exceeded, the broker will log a WARN - level alert with details of the connection and channel on which the threshold has been exceeded, - along with the age of the transaction. - When the openClose or idleClose specified threshold value is exceeded, the broker will - throw an exception back to the client connection via the ExceptionListener, log the - action and then close the connection. - The example broker log output shown below is where the idleWarn threshold specified is - lower than the idleClose threshold and the broker therefore logs the idle transaction 3 times - before the close threshold is triggered and the connection closed out. - - - The second example broker log output shown below illustrates the same mechanism operating - on an open transaction. - - -
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- Client Side Effect - After a Close threshold has been exceeded, the trigger client will receive this exception - on its exception - listener, prior to being disconnected: - org.apache.qpid.AMQConnectionClosedException: Error: Idle transaction timed out - [error code 506: resource error] - Any later attempt to use the connection will result in this exception being thrown: - - - Thus clients must be able to handle this case successfully, reconnecting where required and - registering an exception listener on all connections. This is critical, and must be communicated - to client applications by any broker owner switching on transaction timeouts. -
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- Configuration -
- Configuration - The transaction timeouts can be specified when a new virtualhost is created or an exiting - virtualhost is edited. - We would recommend that only warnings are configured at first, which should allow broker - administrators to obtain an idea of the distribution of transaction lengths on their systems, - and configure production settings appropriately for both warning and closure. Ideally - establishing thresholds should be achieved in a representative UAT environment, with clients and - broker running, prior to any production deployment. - It is impossible to give suggested values, due to the large variation in usage depending on - the applications using a broker. However, clearly transactions should not span the expected - lifetime of any client application as this would indicate a hung client. - When configuring warning and closure timeouts, it should be noted that these only apply to - message producers that are connected to the broker, but that a timeout will cause the connection - to be closed - this disconnecting all producers and consumers created on that connection. - This should not be an issue for environments using Mule or Spring, where connection - factories can be configured appropriately to manage a single MessageProducer object per JMS - Session and Connection. Clients that use the JMS API directly should be aware that sessions - managing both consumers and producers, or multiple producers, will be affected by a single - producer hanging or leaving a transaction idle or open, and closed, and must take appropriate - action to handle that scenario. -
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