You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@cassandra.apache.org by "Daniel Kluesing (JIRA)" <ji...@apache.org> on 2010/07/20 18:59:53 UTC
[jira] Created: (CASSANDRA-1305) Slow query log
Slow query log
--------------
Key: CASSANDRA-1305
URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
Project: Cassandra
Issue Type: New Feature
Reporter: Daniel Kluesing
Priority: Minor
If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Issue Comment Edited: (CASSANDRA-1305) Slow query log
Posted by "Daniel Kluesing (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/CASSANDRA-1305?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12890323#action_12890323 ]
Daniel Kluesing edited comment on CASSANDRA-1305 at 7/20/10 1:02 PM:
---------------------------------------------------------------------
There are lots of knobs to tune (row cache, key cache, index sample size, bloom filter buckets, network, disk, heap) Figuring out what to tune under load isn't always obvious. Turning on debug logging under load has heisenberg effect of shifting bottlenecks around. The attached patch is a simple slow query logger to log information about what queries that take longer than some threshold did that took so long. I've found it useful for pinpointing bottlenecks under load and figuring out which knobs need tweaking. This patch only instruments the get_slice command and the read path. Incrementing the other commands/paths is straightforward, and I can update the patch with the write path.
was (Author: danielkluesing_bk):
There are lots of knobs to tune (row cache, key cache, index sample size, bloom filter buckets, network, disk, heap) Figuring out what to tune under load isn't always obvious. Turning on debug logging under load has heisenberg effect of shifting bottlenecks around. The attached patch is a simple slow query logger to log information about what queries that take longer than some threshold did that took so long. I've found it useful for pinpointing bottlenecks under load and figuring out which knobs need tweaking. This patch only instruments the get_slice command and the read path. Incrementing the other commands/paths is straightforward, and I update the patch with the write path.
> Slow query log
> --------------
>
> Key: CASSANDRA-1305
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
> Project: Cassandra
> Issue Type: New Feature
> Reporter: Daniel Kluesing
> Priority: Minor
> Attachments: trunk-SlowQueryLog.txt
>
>
> If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Updated: (CASSANDRA-1305) Slow query log
Posted by "Jonathan Ellis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/CASSANDRA-1305?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis updated CASSANDRA-1305:
--------------------------------------
Fix Version/s: 0.7.0
(was: 0.7 beta 1)
> Slow query log
> --------------
>
> Key: CASSANDRA-1305
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Daniel Kluesing
> Priority: Minor
> Fix For: 0.7.0
>
> Attachments: trunk-SlowQueryLog.txt
>
>
> If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Commented: (CASSANDRA-1305) Slow query log
Posted by "Jonathan Ellis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/CASSANDRA-1305?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12890862#action_12890862 ]
Jonathan Ellis commented on CASSANDRA-1305:
-------------------------------------------
Daniel, can you update this patch to conform to the style followed by the rest of the code? (see http://wiki.apache.org/cassandra/CodeStyle)
> Slow query log
> --------------
>
> Key: CASSANDRA-1305
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Daniel Kluesing
> Priority: Minor
> Fix For: 0.7 beta 1
>
> Attachments: trunk-SlowQueryLog.txt
>
>
> If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Updated: (CASSANDRA-1305) Slow query log
Posted by "Jonathan Ellis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/CASSANDRA-1305?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis updated CASSANDRA-1305:
--------------------------------------
Fix Version/s: 0.7
Component/s: Core
related: CASSANDRA-1123
> Slow query log
> --------------
>
> Key: CASSANDRA-1305
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Daniel Kluesing
> Priority: Minor
> Fix For: 0.7
>
> Attachments: trunk-SlowQueryLog.txt
>
>
> If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Commented: (CASSANDRA-1305) Slow query log
Posted by "Jonathan Ellis (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/CASSANDRA-1305?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12890870#action_12890870 ]
Jonathan Ellis commented on CASSANDRA-1305:
-------------------------------------------
I also need to be convinced that CLHM + LBQ aren't going to cause too much GC overhead.
Using the key as an id means you can get different requests polluting each others' data. Maybe a threadlocal would work better.
I'm inclined to prefer the CASSANDRA-1123 approach, you get 80% of the benefit for much less overhead.
> Slow query log
> --------------
>
> Key: CASSANDRA-1305
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Reporter: Daniel Kluesing
> Priority: Minor
> Fix For: 0.7 beta 1
>
> Attachments: trunk-SlowQueryLog.txt
>
>
> If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
[jira] Updated: (CASSANDRA-1305) Slow query log
Posted by "Daniel Kluesing (JIRA)" <ji...@apache.org>.
[ https://issues.apache.org/jira/browse/CASSANDRA-1305?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Daniel Kluesing updated CASSANDRA-1305:
---------------------------------------
Attachment: trunk-SlowQueryLog.txt
There are lots of knobs to tune (row cache, key cache, index sample size, bloom filter buckets, network, disk, heap) Figuring out what to tune under load isn't always obvious. Turning on debug logging under load has heisenberg effect of shifting bottlenecks around. The attached patch is a simple slow query logger to log information about what queries that take longer than some threshold did that took so long. I've found it useful for pinpointing bottlenecks under load and figuring out which knobs need tweaking. This patch only instruments the get_slice command and the read path. Incrementing the other commands/paths is straightforward, and I update the patch with the write path.
> Slow query log
> --------------
>
> Key: CASSANDRA-1305
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1305
> Project: Cassandra
> Issue Type: New Feature
> Reporter: Daniel Kluesing
> Priority: Minor
> Attachments: trunk-SlowQueryLog.txt
>
>
> If a query takes a long time, it's nice to know why
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.