[jira] [Commented] (HBASE-4147) StoreFile query usage report

2013-01-10 Thread Andrew Purtell (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13549869#comment-13549869
 ] 

Andrew Purtell commented on HBASE-4147:
---

bq. Meantime, marking this as non-critical and moving out of 0.96 while it is 
w/o a sponsor.

I might be looking at this again in the future in the context of HBASE-6572. 
Deciding what stores to migrate.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
> Attachments: hbase_4147_storefilereport_2011_08_10.pdf, 
> hbase_4147_storefilereport.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira


[jira] [Commented] (HBASE-4147) StoreFile query usage report

2012-12-18 Thread Ted Yu (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13535144#comment-13535144
 ] 

Ted Yu commented on HBASE-4147:
---

Looking at Gary's comment from 10/Aug/11 20:50, can priority of this JIRA be 
lowered now that we have htrace in trunk ?

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Critical
> Fix For: 0.96.0
>
> Attachments: hbase_4147_storefilereport_2011_08_10.pdf, 
> hbase_4147_storefilereport.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira


[jira] [Commented] (HBASE-4147) StoreFile query usage report

2012-03-25 Thread Otis Gospodnetic (Commented) (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13238035#comment-13238035
 ] 

Otis Gospodnetic commented on HBASE-4147:
-

Yes, +1 for publishing in JMX.  We need that for our SPM for HBase monitoring 
service, for example.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Critical
> Fix For: 0.96.0
>
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: 
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2012-03-24 Thread Lars Hofhansl (Commented) (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13237708#comment-13237708
 ] 

Lars Hofhansl commented on HBASE-4147:
--

Should we output the statistics via JMX as well?

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Critical
> Fix For: 0.96.0
>
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: 
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-09-14 Thread Otis Gospodnetic (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13104623#comment-13104623
 ] 

Otis Gospodnetic commented on HBASE-4147:
-

+1 for Todd's tracing idea (is this already in a separate JIRA issue that I 
can't find?)
+1 for what Gary said about using existing mechanisms for publishing metrics, 
so that those of us who already have tools to gather and aggregate data from 
there can just keep using those tools instead of developing new things that 
scrape metrics from additional places.


> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-10 Thread Doug Meil (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13082656#comment-13082656
 ] 

Doug Meil commented on HBASE-4147:
--

With user example #1 of my updated writeup, an example of that happened on the 
dist-list recently.  He still had major compactions scheduled daily, and his 
cluster "got really slow" every day.  If he had summarized 5 min slices 
differentiating system and user activity, he could tell which 
table/reg/cf/storefile was getting system (compaction) activity, etc.

I doubt this answers your particular case, but I think this is a fairly common 
occurrence on with users.

Another example is #3 example of the "degree of uncompaction" stats (e.g., how 
much time is being spent reading each StoreFile.)  This kind of information 
would also help the "HBase as queue" issue that was on the dist-list recently.  
They weren't doing major compactions and apparently had a lot of StoreFiles.

#2 is the "hybrid activity" use-case.  e.g., MR job going on one table while 
there are also random reads on another table.  At least seeing the activity 
during the reporting slice would let you know that something else is happening 
on the cluster and what is getting accessed.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-10 Thread stack (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13082631#comment-13082631
 ] 

stack commented on HBASE-4147:
--

bq. Some of the situations we're currently trying to help application teams 
with are things like: call #1 took 10msec to process, call #2 took 30msec 
to process... Why?

Me and J-D need to be able to answer that question too.

bq. In general, for additional stats that we export, I would like to gently 
encourage a hard-look at whether or not there's a way to incorporate them into 
the metrics framework.

Agree, as much as we can.  We use tsdb here so if a metric, we already have 
ready means for viewing across time.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-10 Thread Gary Helmling (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13082620#comment-13082620
 ] 

Gary Helmling commented on HBASE-4147:
--

I don't want to hijack this issue, but if we're talking about broader tracing 
and monitoring support, I think another inspiration worth looking at is Dapper:
http://research.google.com/pubs/pub36356.html

Some of the situations we're currently trying to help application teams with 
are things like:  call #1 took 10msec to process, call #2 took 30msec to 
process... Why?  We don't have a whole lot at the moment to help in answering 
this.  Better load stats help see what's going on in the cluster from one 
direction.  But it still requires a lot of inferring to see how it ties 
together from the client end.

@Todd, I like the dtrace-like approach.  I think we could start simply with 
something like this and spread and evolve it as we go.  Possibly even growing 
it into distributed tracing.  It seems like that's a broader need so maybe we 
should move that discussion into another issue.

In general, for additional stats that we export, I would like to gently 
encourage a hard-look at whether or not there's a way to incorporate them into 
the metrics framework.  Not everything will fit with this -- it's particularly 
not so great at dynamically named stats (like stats based on store filenames).  
But it does give us an existing framework for collecting, aggregating and 
reporting those stats, with a variety of tools that integrate nicely.  Just 
writing stats to log files requires a whole lot more work to actually make the 
output useful.  Ackowledging sometimes it may be the best/only option though 
(I'm currently patching up the RPC logging to make it a little more useful).  I 
really need to look at metricsv2 and see how much more flexibility it gives us.

@Doug, thanks for the STATSPACK link.  I'll read up on that as well.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-10 Thread Doug Meil (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13082580#comment-13082580
 ] 

Doug Meil commented on HBASE-4147:
--

For those not familiar with Statspack, see this:  
http://www.akadia.com/services/ora_statspack_survival_guide.html

re:  "STATSPACK is a diagnosis tool for instance-wide performance problems; it 
also supports application tuning activities by providing data which identifies 
high-load SQL statements. STATSPACK can be used both proactively to monitor the 
changing load on a system, and also reactively to investigate a performance 
problem."
overview..

re: "The STATSPACK reports we like are from 1 5-minute intervals during a busy 
or peak time, when the performance is at its worst."
That's exactly what I'm talking about...  small intervals.  Not too small, but 
but not too big.

re: "Another common mistake with STATSPACK is to gather snapshots only when 
there is a problem."
That's why this type of reporting should pretty much be 'always on' - you need 
to be able to compare to other points in time.

Again, some things don't translate 1:1 from the RDBMS world, but a lot does.  

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-10 Thread Doug Meil (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13082507#comment-13082507
 ] 

Doug Meil commented on HBASE-4147:
--

Just want to point this out again, "StoreFile" reporting implies that the full 
path is available (table, region, cf, storefile) not just the StoreFile itself. 
 That is pointed out in the doc, but I want to point that out again.

With respect to per-CF metrics, that is better than the current situation of 
only RS level, but I still don't think that covers what I'm proposing there 
isn't a sense of time-cost with the current metrics, nor does it split out 
system vs. app usage.  

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-10 Thread Doug Meil (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13082438#comment-13082438
 ] 

Doug Meil commented on HBASE-4147:
--

Hi Nicolas, I updated another version of this 
"...storefilereport_2011_08_10.pdf" with a "Why" section that has a little more 
background on scenarios.

In a word:  Statspack.  Say what one might about Oracle, that report in was the 
intersection of DBA and developer reporting.  So the answer to the question 
"developer" vs. "DBA" is "both."

re:  HBASE-4057, is "show processlist" a point-in-time command?  It seems to 
be.  That's certainly useful, but it's a little different than the view that 
statspack provides, which does the summary for you.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf, 
> hbase_4147_storefilereport_2011_08_10.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-09 Thread Nicolas Spiegelberg (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13081793#comment-13081793
 ] 

Nicolas Spiegelberg commented on HBASE-4147:


@Doug: what is your goal for this JIRA?  Collecting stats on StoreFile usage is 
really good from a core developer perspective, but it sounds like you want 
better DBA tools.  For example:

1) Get sampling. You just want a way to log every 1k database commands and have 
some collector that displays high level information on get vs put rate, with 
basic filtering capabilities.  
2) Note that we're developing a version of "show processlist" for HBase that 
might also provide the visibility you want (HBASE-4057).  
3) Another option is exporting per-CF metrics in addition to our existing 
per-server metrics.  We have this sorta hacked up for 89 and could give you the 
diffs if you want to finish it off for 92.

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-01 Thread Doug Meil (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13073627#comment-13073627
 ] 

Doug Meil commented on HBASE-4147:
--

Thanks Todd.  I don't think it's that is out of scope.  If something like this 
could serve as the general purpose framework to gather log details, then that 
sounds like a good idea.  I'd like to see some examples that would satisfy the 
use cases in my writeup and any other common performance issues that anybody 
else has.

One expectation I would have is that this would be on for 
development/production clusters - the next question is what level of 
summarization is done out of the box in HBase, and (here we go again) where the 
output goes.  



> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-08-01 Thread Todd Lipcon (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13073606#comment-13073606
 ] 

Todd Lipcon commented on HBASE-4147:


Maybe I'm wandering out of scope, but I've been thinking a bit about statistics 
and monitoring as well recently, and I think it might integrate well with this 
work.

The idea is to define various probe points (to use the dtrace terminology) 
throughout the code. Each probe point would have a name and some predefined set 
of arguments. For example, in the HFile code you might have:
{code}
HFile() {
  this.readTrace = Tracer.get("hfile.read.complete");
}

read() {
...
if (readTrace != null && readTrace.isEnabled()) {
  readTrace.trace(millisSpent, thisHFilePath, blockIdx, ...);
}
{code}

then different things interested in this tracing data can subscribe to the 
trace point -- in this case in order to collect aggregate statistics for each 
30 second period, though other applications would be useful as well. (eg 
dynamically attach a listener to sample some percentage of requests)

Advantage of the above design is that it's flexible, and if off-by-default 
should have no performance impact since it will be basically jitted away

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
> Attachments: hbase_4147_storefilereport.pdf
>
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira




[jira] [Commented] (HBASE-4147) StoreFile query usage report

2011-07-29 Thread Doug Meil (JIRA)

[ 
https://issues.apache.org/jira/browse/HBASE-4147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13072807#comment-13072807
 ] 

Doug Meil commented on HBASE-4147:
--

I think that instrumenting StoreFileScanner by gathering time spent for all the 
'next' and 'seek' calls would do it.  And then on 'close' it would publish the 
detailed record to some internal service that would gather up all the these 
detail records and then periodically dump the summary. 

I'm doing some hand-waving here because we don't want to introduce concurrency 
issues in the publishing process (e.g., publishing to something that is 
synchronized will effectively single-thread StoreFileScanners which would be a 
non-starter), but based on my understanding of the code it seems like this 
would be a fairly targeted change.  

Thoughts?  

> StoreFile query usage report
> 
>
> Key: HBASE-4147
> URL: https://issues.apache.org/jira/browse/HBASE-4147
> Project: HBase
>  Issue Type: Improvement
>Reporter: Doug Meil
>Priority: Minor
>
> Detailed information on what HBase is doing in terms of reads is hard to come 
> by.
> What would be useful is to have a periodic StoreFile query report.  
> Specifically, this could run on a configured interval (e.g., every 30 
> seconds, 60 seconds) and dump the output to the log files.
> This would have all StoreFiles accessed during the reporting period (and with 
> the Path we would also know region, CF, and table), # of times the StoreFile 
> was accessed, the size of the StoreFile, and the total time (ms) spent 
> processing that StoreFile.
> Even this level of summary would be useful to detect a which tables & CFs are 
> being accessed the most, and including the StoreFile would provide insight 
> into relative "uncompaction" (i.e., lots of StoreFiles).
> I think the log-output, as opposed to UI, is an important facet with this.  
> I'm assuming that users will slice and dice this data on their own so I think 
> we should skip any kind of admin view for now (i.e., new JSPs, new APIs to 
> expose this data).  Just getting this to log-file would be a big improvement.
> Will this have a non-zero performance impact?  Yes.  Hopefully small, but yes 
> it will.  However, flying a plane without any instrumentation isn't fun.  :-) 
>  
>  

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira