[jira] [Updated] (OAK-7246) Improve cleanup of locally copied index files

["Amit Jain (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/OAK-7246?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Amit Jain updated OAK-7246:
---------------------------
    Summary: Improve cleanup of locally copied index files  (was: Improve ceanup of locally copied index files)

> Improve cleanup of locally copied index files
> ---------------------------------------------
>
>                 Key: OAK-7246
>                 URL: https://issues.apache.org/jira/browse/OAK-7246
>             Project: Jackrabbit Oak
>          Issue Type: Improvement
>          Components: lucene
>            Reporter: Vikas Saurabh
>            Assignee: Vikas Saurabh
>            Priority: Major
>
> This task is to re-think how should we do clean up of locally copied index files which are no longer in use.
> Current approach:
> # index writers, while creating index files, keep list of currently-being-written files
> ## this list is cleared when a new index writer comes into play
> # index tracker opens new index (at new revision) via observation
> ## while being opened, we also track current dir listing of the local index files
> # during opening new index, the tracker closes the old revision of index reader
> ## during this close, local files noted above during open are purged if ( they don't show up in remote view of the index && they aren't part of currently being written list by index writer)
> This approach, at least in following timeline, would incur extra copying (and as a side-effect also open some index files directly off of remote input stream during CoWs):
> # CoW1 creates [a, b]
> # CoW2 starts and creates [c, d], removes [a, b] from remote
> # CoR1 opens an index due to CoW1
> ## local-list-CoR1 = [a, b, c, d], remote-index-list=[a, b]
> # CoW2 finishes
> # CoW3 creates [e, f], removes [a,b] from remote
> ## CoW-currently-being-written-list=[e,f]
> # CoR2 opens due to CoW2
> ## local-list-CoR2=[a,b,c,d,e,f], remote-index-list=[c,d]
> # CoR1 closes
> ## deletes [c,d] as they aren't in its list of index files ([a,b]) AND aren't part of shared list ([e,f])
> Disclaimer: the timeline might be off a bit (haven't written a test yet... but the basic point is that CoR could be working with a index file set and the new files might have come in twice after CoR - thus shared list doesn't have complete information of new files written in.
> [~chetanm], can you please check the timeline above - I'd try to work on a test case in the mean time.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)