eG Help

The global cache is embedded in the integration node of the IBM Integration Bus. This global cache is a repository for data that you want to reuse. For example, you can use a global cache in WebSphere MQ message flows to store correlation information for use beyond a specific message flow node, instance of a message flow, integration server, or integration node. The cache facilitates sharing of data across processes (both in the same integration node, and across integration nodes) and eliminates the need for an alternative solution, such as a database. You can use one message flow node to store data in the global cache, then a second node (in the same message flow or a separate flow), can retrieve that data from the global cache.

You can use a message flow node to interact with the global cache. Interactions with the cache happen outside the message flow transaction, and are committed immediately. If an exception is thrown downstream of the node that interacts with the cache, the cache interactions are not rolled back.

A global cache is said to be effectively utilized only if it is able to service the maximum number of requests to the IBM Integration Bus; this greatly reduces direct data accesses and related overheads, and thus improving the server performance. On the contrary, ineffective cache usage can be the key contributor to a slowdown or degradation in server performance, as it increases direct data accesses.

This test monitors each global cache of the IBM Integration Bus and reports its usage - in terms of its request serving ability. In the process, the test proactively alerts administrators to the under-utilization of the global cache and the failures in connecting to the cache, and helps them quickly initiate corrective measures.

Measurement	Description	Measurement Unit	Interpretation
connects	Indicates the number of successful attempts that were made from the integration server to this global cache during the last measurement period.	Number
mapReads	Indicates the number of read operations that were completed by message flows in the integration server on this global cache during the last measurement period.	Number	A high value is desired for this measure. A low value or a consistent drop in this value is a cause for concern, as it indicates ineffective cache usage. This means high direct accesses of data, and poor server performance. One of the common reasons for bad cache usage is improper cache size. A cache that does not have sufficient space to accommodate entries will not be able to service requests effectively. You may hence have to allocate more space to the cache or free-up space in the cache to accommodate more entries.
mapWrites	Indicates the number of write operations that were completed by message flows in the integration server on this global cache during the last measurement period.	Number	This measure is incremented when adding or updating an entry in the cache. A high value is desired for this measure. A low value or a consistent drop in this value is a cause for concern, as it indicates ineffective cache usage. This means high disk accesses, and poor server performance. One of the common reasons for bad cache usage is improper cache size. A cache that does not have sufficient space to accommodate entries will not be able to service requests effectively. You may hence have to allocate more space to the cache or free-up space in the cache to accommodate more entries.
mapRemoves	Indicates the number of remove operations that were completed by message flows in the integration server on this global cache during the last measurement period.	Number	This measure is incremented when an entry is removed/updated from the cache.
failedAction	Indicates the number of failed map operations by message flows in the integration server on this global cache during the last measurement period.	Number
mapsUsed	Indicates the total number of maps used by message flows in the integration server on this global cache during the last measurement period.	Number
connectionFailures	Indicates the number of failed attempts to connect from the integration server to the global cache during the last measurement period.	Number	A low value is desired for this measure. A high value or a consistent increase in this value is a cause for concern, as it indicates ineffective cache usage.
totalMapActions	Indicates the number of map operations that were completed by message flows in the integration server on the global cache during the last measurement period.	Number	The value of this measure includes reads, writes, removes, and key checks.