[ 
https://issues.apache.org/jira/browse/SOLR-665?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12617682#action_12617682
 ] 

Yonik Seeley commented on SOLR-665:
-----------------------------------

bq. It's fine to have a custom FifoCacheMap (or whatever name you like) class 
that does not implement java.util.Map.

Right.  Any solr cache must currently implement the SolrCache interface, and 
LinkedHashMap is simply an implementation detail of the LRUCache implementation 
of SolrCache (which has no relationship to the Map interface).

> FIFO Cache (Unsynchronized): 9x times performance boost
> -------------------------------------------------------
>
>                 Key: SOLR-665
>                 URL: https://issues.apache.org/jira/browse/SOLR-665
>             Project: Solr
>          Issue Type: Improvement
>    Affects Versions: 1.3
>         Environment: JRockit R27 (Java 6)
>            Reporter: Fuad Efendi
>         Attachments: FIFOCache.java
>
>   Original Estimate: 672h
>  Remaining Estimate: 672h
>
> Attached is modified version of LRUCache where 
> 1. map = new LinkedHashMap(initialSize, 0.75f, false) - so that 
> "reordering"/true (performance bottleneck of LRU) is replaced to 
> "insertion-order"/false (so that it became FIFO)
> 2. Almost all (absolutely unneccessary) synchronized statements commented out
> See discussion at 
> http://www.nabble.com/LRUCache---synchronized%21--td16439831.html
> Performance metrics (taken from SOLR Admin):
> LRU
> Requests: 7638
> Average Time-Per-Request: 15300
> Average Request-per-Second: 0.06
> FIFO:
> Requests: 3355
> Average Time-Per-Request: 1610
> Average Request-per-Second: 0.11
> Performance increased 9 times which roughly corresponds to a number of CPU in 
> a system, http://www.tokenizer.org/ (Shopping Search Engine at Tokenizer.org)
> Current number of documents: 7494689
> name:          filterCache  
> class:        org.apache.solr.search.LRUCache  
> version:      1.0  
> description:  LRU Cache(maxSize=10000000, initialSize=1000)  
> stats:        lookups : 15966954582
> hits : 16391851546
> hitratio : 0.102
> inserts : 4246120
> evictions : 0
> size : 2668705
> cumulative_lookups : 16415839763
> cumulative_hits : 16411608101
> cumulative_hitratio : 0.99
> cumulative_inserts : 4246246
> cumulative_evictions : 0 
> Thanks

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to