Home | About | Sematext search-lucene.com search-hadoop.com
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB
 Search Hadoop and all its subprojects:

Switch to Threaded View
HBase >> mail # user >> Warning messages in hbase logs


Copy link to this message
-
Re: Warning messages in hbase logs
Vimal,
In my case, for a single client my queries take less than a second (sub-second performance is  on what we were shooting for).
But the same queries when run concurrently gives completely degraded performance. That is the reason I wrote that no-op test case which I have attached in the test HBASE-9410 bug. So many queries trying to execute on a region lead to some sort of lock contentions, is my guess which is causing the slow performance. 
My test case runs fine on 0.95.2 but on 0.94.x even for about 8 concurrent clients it is very high and I see these errors in the log.
You should also try running the test case. You will see bad performance even though the coprocessor function does not do anything.
 
Regards,
- kiru
Kiru Pakkirisamy | webcloudtech.wordpress.com
________________________________
 From: Vimal Jain <[EMAIL PROTECTED]>
To: Kiru Pakkirisamy <[EMAIL PROTECTED]>
Cc: Himanshu Vashishtha <[EMAIL PROTECTED]>; "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>; lars hofhansl <[EMAIL PROTECTED]>
Sent: Wednesday, October 23, 2013 10:50 PM
Subject: Re: Warning messages in hbase logs
 
Hi Kiru,
Can you please elaborate on this ?
On Mon, Oct 21, 2013 at 5:30 PM, Vimal Jain <[EMAIL PROTECTED]> wrote:

Hi Kiru,
>Thanks for the reply.
>My understanding is not very clear  with respect to these warning messages in region server logs.
>When i read documentation , it says its related to slow query logs.
>So is it a issue in earlier versions of hbase and is fixed in 0.96 or is it an issue in my configuration and i have to set some parameters to prevent this?
>Please help in understanding the exact issue.
>
>
>
>
>On Sat, Oct 19, 2013 at 3:31 AM, Kiru Pakkirisamy <[EMAIL PROTECTED]> wrote:
>
>Vimal,
>>Maybe you should try running the test case for HBASE-9410 (with some modifications) and report back.
>>This way Lars/committers/contributors can work on this bug with confirmation.
>>
>>
>>
>>The test case makes a coprocessor call (which does nothing) on a table with regions in all the region servers.
>>Feel free to send me any email in this regards. 
>> 
>>Regards,
>>- kiru
>>
>>
>>
>>Kiru Pakkirisamy | webcloudtech.wordpress.com
>>
>>
>>________________________________
>> From: Vimal Jain <[EMAIL PROTECTED]>
>>To: Himanshu Vashishtha <[EMAIL PROTECTED]>
>>Cc: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>; Kiru Pakkirisamy <[EMAIL PROTECTED]>; lars hofhansl <[EMAIL PROTECTED]>
>>Sent: Thursday, October 17, 2013 9:39 PM
>>
>>Subject: Re: Warning messages in hbase logs
>>
>>
>>
>>Hi.
>>I am still getting these warnings in region server logs.
>>I am still using hbase 0.94.7.
>>Is there any impact of these warning messages ?
>>
>>
>>
>>
>>On Thu, Sep 26, 2013 at 11:19 PM, Himanshu Vashishtha <[EMAIL PROTECTED]> wrote:
>>
>>
>>>
>>>
>>>
>>>
>>>On Thu, Sep 26, 2013 at 4:07 AM, Kiru Pakkirisamy <[EMAIL PROTECTED]> wrote:
>>>
>>>I was on 0.94.11 and still got the same msgs as Vimal. 
>>>>Ultimately, I moved to 0.95.2.
>>>>
>>> 
>>>You know it is a dev release, right? 
>>>
>>>
>>>
>>>
>>>Regards,
>>>>- kiru
>>>>
>>>>
>>>>Kiru Pakkirisamy | webcloudtech.wordpress.com
>>>>
>>>>
>>>>
>>>>________________________________
>>>> From: lars hofhansl <[EMAIL PROTECTED]>
>>>>To: Vimal Jain <[EMAIL PROTECTED]>; "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
>>>>Cc: Kiru Pakkirisamy <[EMAIL PROTECTED]>
>>>>Sent: Wednesday, September 25, 2013 9:46 PM
>>>>
>>>>Subject: Re: Warning messages in hbase logs
>>>>
>>>>
>>>>You probably ran into
>>>>[HBASE-6870] - HTable#coprocessorExec always scan the whole table (0.94.8)
>>>>
>>>>Or maybe one of these:
>>>>
>>>>[HBASE-8806] - Row locks are acquired repeatedly in HRegion.doMiniBatchMutation for duplicate rows. (0.94.10)
>>>>[HBASE-8639] - Poor performance of htable#getscanner in multithreaded environment due to DNS.getDefaultHost() being called in ScannerCallable#prepare() (0.94.9)
>>>>[HBASE-9087] - Handlers being blocked during reads (0.94.11)
>>>>
>>>>
>>>
Thanks and Regards,
Vimal Jain
NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB