[
https://issues.apache.org/jira/browse/CASSANDRA-18111?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17855958#comment-17855958
]
Stefan Miklosovic edited comment on CASSANDRA-18111 at 6/18/24 2:40 PM:
------------------------------------------------------------------------
I forgot to add that another solution would be to load all the sizes on the
very first loading - upon node's start. Plus every snapshot taken after that
would pre-compute the sizes too. This approach is also quite desirable because
if there is e.g. a jmx method to "restart SnapshotManager" which would reload
all the snapshots, then all these sizes would be pre-computed again. Hence if
somebody just removes some data from a snapshot accidentally (or not), all it
takes to have "the right sizes" again would be to reload it all.
was (Author: smiklosovic):
I forgot to add that another solution would be to load all the sizes on the
very first loading - upon node's start. Plus every snapshot taken after that
would pre-compute the sizes too.
> Cache snapshots in memory
> -------------------------
>
> Key: CASSANDRA-18111
> URL: https://issues.apache.org/jira/browse/CASSANDRA-18111
> Project: Cassandra
> Issue Type: Improvement
> Components: Local/Snapshots
> Reporter: Paulo Motta
> Assignee: Stefan Miklosovic
> Priority: Normal
> Fix For: 5.x
>
> Time Spent: 1h 10m
> Remaining Estimate: 0h
>
> Everytime {{nodetool listsnapshots}} is called, all data directories are
> scanned to find snapshots, what is inefficient.
> For example, fetching the
> {{org.apache.cassandra.metrics:type=ColumnFamily,name=SnapshotsSize}} metric
> can take half a second (CASSANDRA-13338).
> This improvement will also allow snapshots to be efficiently queried via
> virtual tables (CASSANDRA-18102).
> In order to do this, we should:
> a) load all snapshots from disk during initialization
> b) keep a collection of snapshots on {{SnapshotManager}}
> c) update the snapshots collection anytime a new snapshot is taken or cleared
> d) detect when a snapshot is manually removed from disk.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org
For additional commands, e-mail: commits-h...@cassandra.apache.org
