Details
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Improvement
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Status: Closed
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Major
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Resolution: Fixed
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2.5
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Windows 2008, tomcat application server, SQL Server 2008 database server
Description
We are adding a large number of documents to a jackrabbit 2.5 database repository. We are using the bundle.MSSqlPersistenceManager and we are seeing a large number of SQL queries (300+) when adding a single folder, file, and file content. This appears to create a significant performance bottleneck when adding documents when the repository size is over 300k documents/nodes. The repository structure is a hierarchy with less than 1000k child nodes per parent. The following is an example structure of the repo with the (New child folder) representing the new content being added.
– Root node
– Parent node
--New child folder (mix:versionable,mix:lockable)
--new file (mix:versionable,mix:lockable)
--new document content
--Existing Child Folder
– Parent node
The vast majority of the 200-300+ queries that execute when adding a node look like the following:
exec sp_execute 2,0x5740D9A36F2E4032BFF0BA652D89FFB8
exec sp_execute 2,0xBBFE059BF7E44947A8B0858F3CE33DB8
exec sp_execute 2,0xC2AD22DBE1DB43A083BCA1B2C94E07CC
The majority of the queries that are executed appear to be related to versioning. When a node is added the version history for the node stored/saved, the parent node is saved, which ultimately cascades and saves all children of the parent, so adding a child node saves the parent and all other children.
We have created a patch for jackrabbit-core 2.5.0 to prevent the cascade to store all other child nodes when saving/storing the version history of a new node. This cuts the number of queries that are executed in half. Does anyone see a problem with this technique? All unit tests are still passing.