[
https://issues.apache.org/jira/browse/CASSANDRA-12183?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17736527#comment-17736527
]
Stefan Miklosovic edited comment on CASSANDRA-12183 at 6/23/23 3:23 PM:
------------------------------------------------------------------------
for 4.1 it is the same stuff but for 4.0 and sooner it is a little bit tricky.
In 4.0, the type of id field in system.compaction_history is "uuid" (1) but it
is inserted there as "time uuid" (2). So, if we went with passing UUID to that
table, we would start to insert there UUIDs instead of time uuids and we are
changing the behavior.
the original id of UUID type we want to use and pass to system table comes from
here (3) but in 4.1 and trunk it is TimeUUID (4) and it came into existence by
(5).
So, in a nutshell, I think we may do this for 4.1 at most and we leave older
branches untouched.
Thoughts [~brandon.williams] [~jjirsa]
(1)
[https://github.com/apache/cassandra/blob/cassandra-4.0/src/java/org/apache/cassandra/db/SystemKeyspace.java#L270]
(2)
[https://github.com/apache/cassandra/blob/cassandra-4.0/src/java/org/apache/cassandra/db/SystemKeyspace.java#L568]
(3)
[https://github.com/apache/cassandra/blob/cassandra-4.0/src/java/org/apache/cassandra/db/lifecycle/LogFile.java#L94]
(4)
[https://github.com/apache/cassandra/blob/cassandra-4.1/src/java/org/apache/cassandra/db/lifecycle/LogFile.java#L96]
(5) [https://issues.apache.org/jira/browse/CASSANDRA-17176]
was (Author: smiklosovic):
for 4.1 it is the same stuff but for 4.0 and sooner it is a little bit tricky.
In 4.0, the type of id field in system.compaction_history is "uuid" (1) but it
is inserted there as "time uuid" (2). So, if we went with passing UUID to that
table, we would start to insert there UUIDs instead of time uuids and we are
changing the behavior.
the original id of UUID type we want to use and pass to system table comes from
here (3) but in 4.1 and trunk it is TimeUUID (4) and it came into existence by
(5).
So, in a nutshell, I think we may do this for 4.1 at most and we leave older
branches untouched.
Thoughts [~brandon.williams]
(1)
[https://github.com/apache/cassandra/blob/cassandra-4.0/src/java/org/apache/cassandra/db/SystemKeyspace.java#L270]
(2)
[https://github.com/apache/cassandra/blob/cassandra-4.0/src/java/org/apache/cassandra/db/SystemKeyspace.java#L568]
(3)
[https://github.com/apache/cassandra/blob/cassandra-4.0/src/java/org/apache/cassandra/db/lifecycle/LogFile.java#L94]
(4)
[https://github.com/apache/cassandra/blob/cassandra-4.1/src/java/org/apache/cassandra/db/lifecycle/LogFile.java#L96]
(5) [https://issues.apache.org/jira/browse/CASSANDRA-17176]
> compaction_history system table does not capture all historical compaction
> sessions
> -----------------------------------------------------------------------------------
>
> Key: CASSANDRA-12183
> URL: https://issues.apache.org/jira/browse/CASSANDRA-12183
> Project: Cassandra
> Issue Type: Bug
> Components: Legacy/Observability, Local/Compaction
> Reporter: Wei Deng
> Assignee: Stefan Miklosovic
> Priority: Normal
> Fix For: 5.x
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> It appears that some compaction sessions are not recorded in
> system.compaction_history table after the compaction session successfully
> finishes.
> The following is an example (test by simply running +cassandra-stress write
> n=100000000+):
> {noformat}
> automaton@wdengdse50google-98425b985-3:~$ nodetool compactionstats
> pending tasks: 46
> id compaction type keyspace
> table completed total unit progress
> fa8a4f30-4884-11e6-b916-1dbd340a212f Compaction keyspace1
> standard1 4233184044 4774209875 bytes 88.67%
> 91e30d21-4887-11e6-b916-1dbd340a212f Compaction keyspace1
> standard1 836983029 889773060 bytes 94.07%
> Active compaction remaining time : 0h00m35s
> automaton@wdengdse50google-98425b985-3:~$ nodetool compactionstats
> pending tasks: 47
> id compaction type keyspace
> table completed total unit progress
> fa8a4f30-4884-11e6-b916-1dbd340a212f Compaction keyspace1
> standard1 4353251539 4774209875 bytes 91.18%
> 28359094-4888-11e6-b916-1dbd340a212f Compaction keyspace1
> standard1 49732274 4071652280 bytes 1.22%
> Active compaction remaining time : 0h04m24s
> {noformat}
> At this point you know the previous compaction session
> 91e30d21-4887-11e6-b916-1dbd340a212f finished and confirmation can be found
> from debug.log
> {noformat}
> automaton@wdengdse50google-98425b985-3:~$ grep
> 91e30d21-4887-11e6-b916-1dbd340a212f /var/log/cassandra/debug.log
> DEBUG [CompactionExecutor:4] 2016-07-12 23:22:58,674 CompactionTask.java:146
> - Compacting (91e30d21-4887-11e6-b916-1dbd340a212f)
> [/var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-290-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-279-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-281-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-280-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-284-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-283-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-287-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-292-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-286-big-Data.db:level=0,
>
> /var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-289-big-Data.db:level=0,
> ]
> DEBUG [CompactionExecutor:4] 2016-07-12 23:26:56,054 CompactionTask.java:217
> - Compacted (91e30d21-4887-11e6-b916-1dbd340a212f) 10 sstables to
> [/var/lib/cassandra/data/keyspace1/standard1-9c02e9c1487c11e6b9161dbd340a212f/mb-293-big,]
> to level=0. 889,773,060 bytes to 890,473,350 (~100% of original) in
> 237,365ms = 3.577703MB/s. 0 total partitions merged to 3,871,921. Partition
> merge counts were {1:3871921, }
> {noformat}
> However, if you query system.compaction_history table or run "nodetool
> compactionhistory | grep 91e30d21-4887-11e6-b916-1dbd340a212f" you will get
> nothing:
> {noformat}
> automaton@wdengdse50google-98425b985-3:~$ cqlsh -u cassandra
> Password:
> Connected to dse50 at 127.0.0.1:9042.
> [cqlsh 5.0.1 | Cassandra 3.0.7.1158 | DSE 5.0.0 | CQL spec 3.4.0 | Native
> protocol v4]
> Use HELP for help.
> cassandra@cqlsh> select * from system.compaction_history where
> id=91e30d21-4887-11e6-b916-1dbd340a212f;
> id | bytes_in | bytes_out | columnfamily_name | compacted_at | keyspace_name
> | rows_merged
> ----+----------+-----------+-------------------+--------------+---------------+-------------
> (0 rows)
> automaton@wdengdse50google-98425b985-3:~$ nodetool flush system
> automaton@wdengdse50google-98425b985-3:~$ nodetool compactionhistory | grep
> 91e30d21-4887-11e6-b916-1dbd340a212f
> {noformat}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
