Portal Cache Tuning with Portal Cache Viewer Open Mic 10/01/2014

Transcription

1 Portal Cache Tuning with Portal Cache Viewer Open Mic 10/01/2014 Klaus Nossek Software Engineer, WebSphere Portal Dr. Andreas Wickenhaeuser Software Engineer, WebSphere Portal IBM Collaboration Solutions Powered by IBM SmartCloud Meetings 2014 IBM Corporation

2 Agenda What is Caching? Overview on the Caching Architecture of WebSphere Portal Application Caches Example of Portal Cache Tuning The Cache Viewer Portlet Key Performance Indicators of Caches Advanced Features of Cache Viewer Cache Hierarchies Q&A IBM Corporation

3 What is caching? A cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere. If requested data is contained in the cache (cache hit), this request can be served by simply reading the cache, which is comparatively faster. Otherwise (cache miss), the data has to be recomputed or fetched from its original storage location, which is comparatively slower. Hence, the greater the number of requests that can be served from the cache, the faster the overall system performance becomes. Cache (computing), Wikipedia IBM Corporation

4 Caching Benefits Portal Caches save a lot of Hardware Software (licensing costs) CPU processing Network bandwidth Response time Increases throughput & the number of users that Portal can serve Without any caching, Portal would be inoperable IBM Corporation

5 Caching in WebSphere Portal - HTTP Responses Web Pages Images CSS JavaScript - Private & Public - HTTP Responses - Public Only - HTTP Responses from a portlet - Internal Portal & WCM data - Backend query results - Custom application data IBM Corporation

6 Caching in WebSphere Portal Server Load & Response Time Cached Content Size HTTP Responses HTML Fragments Java Objects IBM Corporation

7 Application Caches IBM Corporation

8 Application Caches Portal Fragment Cache - Caches the HTML output of a single portlet When the whole page cannot be cached When a portlet requires a large amount of CPU to render Portal Caches Backend queries are expensive Object creation is expensive WCM Caches Raw Content Rendered Content Content hierarchy & navigation Security & access inheritance JCR query results Application Caches Application specific caches IBM Corporation

9 Example: Portal Cache Tuning High Response Time!!! Huge Traffic The clients experience poor response time IBM Corporation

10 Example: Portal Cache Tuning Cache Viewer Portlet Tune the caches to reduce the number of requests hitting the backend IBM Corporation

11 Example: Portal Cache Tuning Good Response Time!!! Low Traffic IBM Corporation

12 Availability of WebSphere Portal Cache Viewer For WebSphere Portal For WebSphere Portal In addition, the WebSphere Portal 8.5 Tuning guide The Cache Viewer is available as PAA file. After installation, the Cache Viewer is accessible under the path WebSphere Portal > Portal Analysis > Cache Viewer IBM Corporation

13 Key Performance Indicators of Caches Size The number of entries in the cache. Capacity The maximum number of entries a cache can hold. Lookup count How often an entry was queried in the cache. Hitrate The relation between cache hits and cache lookups. The Cache Viewer can be used in the following way: In the Simple View, look for caches annotated with an exclamation mark. View only full or almost full caches. Refer to the WebSphere Portal 8.5 Performance Tuning Guide for more information about the caches of interest IBM Corporation

14 Scope of the Cache Viewer The Cache Viewer presents a list of caches containing: Caches managed by the WebSphere Portal Cache Manager service. These caches have a broad range of characteristics, some of them are based on WebSphere DynaCaches. The initial configuration values of these caches can be found in the file <Portal profile>/portalserver/config/cachemanagerservice.properties The configuration values can be either changed in this file or as custom properties of the resource environment provider WP CacheManagerService. WebSphere DynaCaches managed outside the WebSphere Portal Cache Manager service. Only caches running in the local Java virtual machine can be monitored by the Cache Viewer. In contrast to the WebSphere Portal Cache Viewer, the WebSphere cache monitor can be used only to monitor DynaCaches IBM Corporation

15 Advanced Features of Cache Viewer Besides others, the extended view of the Cache Viewer provides the following: Cache implementation information A view to the cache content in case of DynaCaches More statistics information Information how the cache is managed As you can see, the majority of caches is managed by the Cache Manager service. In addition, key cache statistics information is provided as comma separated list for further processing IBM Corporation

16 Cache hierarchies, aggregates Often, multiple caches are used together. In WebSphere Portal, we can distinguish between aggregates and first level caches: Creating an aggregated object out of cacheable objects and cache this object. For more information see the WebSphere Portal 8.5 Performance Tuning Guide. There, together with a description of the caches, an overview is given how the caches relate to each other IBM Corporation

17 Cache hierarchies, first level caches Entries can be stored in first level caches with fast access. If they are not found in the first level cache, they are searched in the second level cache. In WebSphere Portal, the second level cache is typically based on a DynaCache IBM Corporation

18 Cache hierarchies, first level caches The Cache Viewer shows first level, second level relations. Typically, the second level cache has lower access rates and much lower hit rates than the first level cache. Some first level caches also store information about cache misses. In this case, the first level cache can contain much more entries than its second level cache IBM Corporation

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