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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: Multiple counters value after restart
Date Thu, 01 Nov 2012 11:53:07 GMT
"Can you try it thought, or run a repair ?"

Repairing didn't help

"My first thought is to use QUOURM"

This fix the problem. However, my data is probably still inconsistent, even
if I read now always the same value. The point is that I can't handle a
crash with CL.QUORUM, I can't even restart a node...

I will add a third server.

  "But isn't Cassandra suppose to handle a server crash ? When a server
crashes I guess it don't drain before..."

"I was asking to understand how you did the upgrade."

Ok. On my side I am just concern about the possibility of using counters
with CL.ONE and correctly handle a crash or restart without a drain.

Alain



2012/11/1 aaron morton <aaron@thelastpickle.com>

> "What CL are you using ?"
>
> I think this can be what causes the issue. I'm writing and reading at CL
> ONE. I didn't drain before stopping Cassandra and this may have produce a
> fail in the current counters (those which were being written when I stopped
> a server).
>
> My first thought is to use QUOURM. But with only two nodes it's hard to
> get strong consistency using  QUOURM.
> Can you try it thought, or run a repair ?
>
> But isn't Cassandra suppose to handle a server crash ? When a server
> crashes I guess it don't drain before...
>
> I was asking to understand how you did the upgrade.
>
> Cheers
>
>   -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 1/11/2012, at 11:39 AM, Alain RODRIGUEZ <arodrime@gmail.com> wrote:
>
> "What version of cassandra are you using ?"
>
> 1.1.2
>
> "Can you explain this further?"
>
> I had an unexplained amount of reads (up to 1800 r/s and 90 Mo/s) on one
> server the other was doing about 200 r/s and 5 Mo/s max. I fixed it by
> rebooting the server. This server is dedicated to cassandra. I can't tell
> you more about it 'cause I don't get it... But a simple Cassandra restart
> wasn't enough.
>
> "Was something writing to the cluster ?"
>
> Yes we are having some activity and perform about 600 w/s.
>
> "Did you drain for the upgrade ?"
>
> We upgrade a long time ago and to 1.1.2. This warning is about the version
> 1.1.6.
>
> "What changes did you make ?"
>
> In the cassandra.yaml I just change the "compaction_throughput_mb_per_sec"
> property to slow down my compaction a bit. I don't think the problem come
> from here.
>
> "Are you saying that a particular counter column is giving different
> values for different reads ?"
>
> Yes, this is exactly what I was saying. Sorry if something is wrong with
> my English, it's not my mother tongue.
>
> "What CL are you using ?"
>
> I think this can be what causes the issue. I'm writing and reading at CL
> ONE. I didn't drain before stopping Cassandra and this may have produce a
> fail in the current counters (those which were being written when I stopped
> a server).
>
> But isn't Cassandra suppose to handle a server crash ? When a server
> crashes I guess it don't drain before...
>
> Thank you for your time Aaron, once again.
>
> Alain
>
>
>
> 2012/10/31 aaron morton <aaron@thelastpickle.com>
>
>> What version of cassandra are you using ?
>>
>>  I finally restart Cassandra. It didn't solve the problem so I stopped
>>> Cassandra again on that node and restart my ec2 server. This solved the
>>> issue (1800 r/s to 100 r/s).
>>
>> Can you explain this further?
>> Was something writing to the cluster ?
>> Did you drain for the upgrade ?
>> https://github.com/apache/cassandra/blob/cassandra-1.1/NEWS.txt#L17
>>
>> Today I changed my cassandra.yml and restart this same server to apply my
>>> conf.
>>
>> What changes did you make ?
>>
>> I just noticed that my homepage (which uses a Cassandra counter and
>>> refreshes every sec) shows me 4 different values. 2 of them repeatedly
>>> (5000 and 4000) and the 2 other some rare times (5500 and 3800)
>>
>> Are you saying that a particular counter column is giving different
>> values for different reads ?
>> What CL are you using ?
>>
>> Cheers
>>
>>   -----------------
>> Aaron Morton
>> Freelance Developer
>> @aaronmorton
>> http://www.thelastpickle.com
>>
>> On 31/10/2012, at 3:39 AM, Jason Wee <peichieh@gmail.com> wrote:
>>
>> maybe enable the debug in log4j-server.properties and going through the
>> log to see what actually happen?
>>
>> On Tue, Oct 30, 2012 at 7:31 PM, Alain RODRIGUEZ <arodrime@gmail.com>wrote:
>>
>>> Hi,
>>>
>>> I have an issue with counters, yesterday I had a lot of ununderstandable
>>> reads/sec on one server. I finally restart Cassandra. It didn't solve the
>>> problem so I stopped Cassandra again on that node and restart my ec2
>>> server. This solved the issue (1800 r/s to 100 r/s).
>>>
>>> Today I changed my cassandra.yml and restart this same server to apply
>>> my conf.
>>>
>>> I just noticed that my homepage (which uses a Cassandra counter and
>>> refreshes every sec) shows me 4 different values. 2 of them repeatedly
>>> (5000 and 4000) and the 2 other some rare times (5500 and 3800)
>>>
>>> Only the counters made today and yesterday are concerned.
>>>
>>> I performed a repair without success. These data are the heart of our
>>> business so if someone had any clue on it, I would be really grateful...
>>>
>>> The sooner the better, I am in production with these random counters.
>>>
>>> Alain
>>>
>>> INFO:
>>>
>>> My environnement is 2 nodes (EC2 large), RF 2, CL.ONE (R & W), Random
>>> Partitioner.
>>>
>>> xxx.xxx.xxx.241    eu-west     1b          Up     Normal  151.95 GB
>>>   50.00%              0
>>> xxx.xxx.xxx.109    eu-west     1b          Up     Normal  117.71 GB
>>>   50.00%              85070591730234615865843651857942052864
>>>
>>> Here is my conf: http://pastebin.com/5cMuBKDt
>>>
>>>
>>>
>>
>>
>
>

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