[
https://issues.apache.org/jira/browse/IGNITE-13143?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Maxim Muzafarov updated IGNITE-13143:
-------------------------------------
Labels: IEP-47 important (was: IEP-47)
> Persistent store defragmentation
> --------------------------------
>
> Key: IGNITE-13143
> URL: https://issues.apache.org/jira/browse/IGNITE-13143
> Project: Ignite
> Issue Type: New Feature
> Components: persistence
> Reporter: Sergey Chugunov
> Priority: Major
> Labels: IEP-47, important
>
> Persistent store enables users to store data of their caches in a durable
> fashion on disk still benefiting from in-memory nature of Apache Ignite. Data
> of caches is stored in files created for every primary or backup partition
> assigned to that node and in an additional file for all user indexes.
> Files in filesystem are allocated lazily (only if some data is actually
> stored to particular partition) and grow automatically when more data is
> added to the cache. But the problem is that files cannot shrink even if all
> data is removed.
> This umbrella ticket covers all other tasks needed to implement simple yet
> effective approach to defragmentation. Detailed discussion could be found in
> [IEP-47|https://cwiki.apache.org/confluence/display/IGNITE/IEP-47%3A+Native+persistence+defragmentation]
> and in corresponding [dev-list
> discussion|http://apache-ignite-developers.2346864.n4.nabble.com/DISCUSSION-IEP-47-Native-persistence-defragmentation-td47717.html]
> but core ideas are as follows:
> # Defragmentation is performed in a special _maintenance_ mode when node
> starts, provides access to some APIs like metrics or JMX management but
> doesn't join the cluster.
> # It is performed by copying all data from all partitions on node to new
> files with automatic compaction. After successful copy old partition files
> are deleted.
> # Metrics on progress of the operation are provided to the user.
> # Operation is fault-tolerant and in case of node failure proceeds after
> node restart.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
