Configuring Broker Server to Use Asynchronous Write Mode
Broker Server can be configured to write data to disk asynchronously. In this mode, Broker Server permits the operating system to cache its disk write operations in memory.
Enabling asynchronous write mode can significantly increase the performance of guaranteed documents. However, it also carries the risk of document loss in the event of a host system failure. If the host fails, any guaranteed documents that the operating system had written to cache, but had not yet committed to disk, are lost. If you require a high degree of reliability, you should not enable asynchronous write mode.
To enable the asynchronous write mode, you must modify the storage session parameters in the Broker Server configuration file (awbroker.cfg). If you are using separate storage sessions, you can enable asynchronous mode for the run-time session, the configuration session, or both sessions.
Use the
batchmode argument to enable batching for the asynchronous disk writes. For information about configuring the batch mode, see
webMethods Broker Server Configuration Parameters.
To configure asynchronous-write mode
1. Stop the Broker Server.
2. On the machine where Broker Server is installed, locate the Broker Server's configuration file (awbroker.cfg) and make a backup copy of it.
3. Open the configuration file with a text editor and locate the session-config and session-data parameters, which are underscored in the example below. (If you are running a combined storage session, your configuration file will contain only the session-config parameter.)
.
.
.
snmp=1
eventlog=1
internal=1
session-config=qs:///var/opt/BrokerStorage/BrokerConfig.qs
session-data=qs:///var/opt/BrokerStorage/BrokerData.qs?max_cache_size=512
4. To specify the cache size for a storage session, append the "async" argument to the session's URL.
Because the storage session is specified as a URL, you must include the "?" separator if the async argument is the first argument in the query string. If the URL already includes a query string, use the "," character to separate the async argument from the other arguments in the string. Both forms are shown in the example below.
.
.
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snmp=1
eventlog=1
internal=1
session-config=qs:///var/opt/BrokerStorage/BrokerConfig.qs?async
session-
data=qs:///var/opt/BrokerStorage/BrokerData.qs?max_cache_size=512,async
5. Save the configuration file.
6. Restart the Broker Server.