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Posted to solr-user@lucene.apache.org by Rallavagu <ra...@gmail.com> on 2015/10/08 04:39:30 UTC
tlog replay
Solr 4.6.1, single shard, 4 node cloud, 3 node zk
Like to understand the behavior better when large number of updates
happen on leader and it generates huge tlog (14G sometimes in my case)
on other nodes. At the same time leader's tlog is few KB. So, what is
the rate at which the changes from transaction log are applied at nodes?
The autocommit interval is set to 15 seconds after going through
https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
Thanks
Re: tlog replay
Posted by Rallavagu <ra...@gmail.com>.
Erick,
Actually, configured autocommit to 15 seconds and openSearcher is set to
false. Neither 2 nor 3 happened. However, softCommit is set to 10 min.
<autoCommit>
<maxTime>${solr.autoCommit.maxTime:15000}</maxTime>
<openSearcher>false</openSearcher>
</autoCommit>
Working on upgrading to 5.3 which will take a bit of time and trying to
get this under control until that time.
On 10/8/15 5:28 PM, Erick Erickson wrote:
> right, so the scenario is
> 1> somehow you didn't do a hard commit (openSearcher=true or false
> doesn't matter) for a really long time while indexing.
> 2> Solr abnormally terminated.
> 3> When Solr started back up it replayed the entire log.
>
> How <1> happened is the mystery though. With a hard commit
> (autocommit) interval of 15 seconds that's weird.
>
> The message indicates something like that happened. In very recent
> Solr versions, the log will have
> progress messages printed that'll help see this is happening.
>
> Best,
> Erick
>
> On Thu, Oct 8, 2015 at 12:23 PM, Rallavagu <ra...@gmail.com> wrote:
>> As a follow up.
>>
>> Eventually the tlog file is disappeared (could not track the time it took to
>> clear out completely). However, following messages were noticed in
>> follower's log.
>>
>> 5120638 [recoveryExecutor-14-thread-2] WARN org.apache.solr.update.UpdateLog
>> – Starting log replay tlog
>>
>> On 10/7/15 8:29 PM, Erick Erickson wrote:
>>>
>>> The only way I can account for such a large file off the top of my
>>> head is if, for some reason,
>>> the Solr on the node somehow was failing to index documents and kept
>>> adding them to the
>>> log for a loooonnngggg time. But how that would happen without the
>>> node being in recovery
>>> mode I'm not sure. I mean the Solr instance would have to be healthy
>>> otherwise but just not
>>> able to index docs which makes no sense.
>>>
>>> The usual question here is whether there were any messages in the solr
>>> log file indicating
>>> problems while this built up.
>>>
>>> tlogs will build up to very large sizes if there are very long hard
>>> commit intervals, but I don't
>>> see how that interval would be different on the leader and follower.
>>>
>>> So color me puzzled.
>>>
>>> Best,
>>> Erick
>>>
>>> On Wed, Oct 7, 2015 at 8:09 PM, Rallavagu <ra...@gmail.com> wrote:
>>>>
>>>> Thanks Erick.
>>>>
>>>> Eventually, followers caught up but the 14G tlog file still persists and
>>>> they are healthy. Is there anything to look for? Will monitor and see how
>>>> long will it take before it disappears.
>>>>
>>>> Evaluating move to Solr 5.3.
>>>>
>>>> On 10/7/15 7:51 PM, Erick Erickson wrote:
>>>>>
>>>>>
>>>>> Uhm, that's very weird. Updates are not applied from the tlog. Rather
>>>>> the
>>>>> raw doc is forwarded to the replica which both indexes the doc and
>>>>> writes it to the local tlog. So having a 14G tlog on a follower but a
>>>>> small
>>>>> tlog on the leader is definitely strange, especially if it persists over
>>>>> time.
>>>>>
>>>>> I assume the follower is healthy? And does this very large tlog
>>>>> disappear
>>>>> after a while? I'd expect it to be aged out after a few commits of > 100
>>>>> docs.
>>>>>
>>>>> All that said, there have been a LOT of improvements since 4.6, so it
>>>>> might
>>>>> be something that's been addressed in the intervening time.
>>>>>
>>>>> Best,
>>>>> Erick
>>>>>
>>>>>
>>>>>
>>>>> On Wed, Oct 7, 2015 at 7:39 PM, Rallavagu <ra...@gmail.com> wrote:
>>>>>>
>>>>>>
>>>>>> Solr 4.6.1, single shard, 4 node cloud, 3 node zk
>>>>>>
>>>>>> Like to understand the behavior better when large number of updates
>>>>>> happen
>>>>>> on leader and it generates huge tlog (14G sometimes in my case) on
>>>>>> other
>>>>>> nodes. At the same time leader's tlog is few KB. So, what is the rate
>>>>>> at
>>>>>> which the changes from transaction log are applied at nodes? The
>>>>>> autocommit
>>>>>> interval is set to 15 seconds after going through
>>>>>>
>>>>>>
>>>>>> https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
>>>>>>
>>>>>> Thanks
Re: tlog replay
Posted by Erick Erickson <er...@gmail.com>.
right, so the scenario is
1> somehow you didn't do a hard commit (openSearcher=true or false
doesn't matter) for a really long time while indexing.
2> Solr abnormally terminated.
3> When Solr started back up it replayed the entire log.
How <1> happened is the mystery though. With a hard commit
(autocommit) interval of 15 seconds that's weird.
The message indicates something like that happened. In very recent
Solr versions, the log will have
progress messages printed that'll help see this is happening.
Best,
Erick
On Thu, Oct 8, 2015 at 12:23 PM, Rallavagu <ra...@gmail.com> wrote:
> As a follow up.
>
> Eventually the tlog file is disappeared (could not track the time it took to
> clear out completely). However, following messages were noticed in
> follower's log.
>
> 5120638 [recoveryExecutor-14-thread-2] WARN org.apache.solr.update.UpdateLog
> – Starting log replay tlog
>
> On 10/7/15 8:29 PM, Erick Erickson wrote:
>>
>> The only way I can account for such a large file off the top of my
>> head is if, for some reason,
>> the Solr on the node somehow was failing to index documents and kept
>> adding them to the
>> log for a loooonnngggg time. But how that would happen without the
>> node being in recovery
>> mode I'm not sure. I mean the Solr instance would have to be healthy
>> otherwise but just not
>> able to index docs which makes no sense.
>>
>> The usual question here is whether there were any messages in the solr
>> log file indicating
>> problems while this built up.
>>
>> tlogs will build up to very large sizes if there are very long hard
>> commit intervals, but I don't
>> see how that interval would be different on the leader and follower.
>>
>> So color me puzzled.
>>
>> Best,
>> Erick
>>
>> On Wed, Oct 7, 2015 at 8:09 PM, Rallavagu <ra...@gmail.com> wrote:
>>>
>>> Thanks Erick.
>>>
>>> Eventually, followers caught up but the 14G tlog file still persists and
>>> they are healthy. Is there anything to look for? Will monitor and see how
>>> long will it take before it disappears.
>>>
>>> Evaluating move to Solr 5.3.
>>>
>>> On 10/7/15 7:51 PM, Erick Erickson wrote:
>>>>
>>>>
>>>> Uhm, that's very weird. Updates are not applied from the tlog. Rather
>>>> the
>>>> raw doc is forwarded to the replica which both indexes the doc and
>>>> writes it to the local tlog. So having a 14G tlog on a follower but a
>>>> small
>>>> tlog on the leader is definitely strange, especially if it persists over
>>>> time.
>>>>
>>>> I assume the follower is healthy? And does this very large tlog
>>>> disappear
>>>> after a while? I'd expect it to be aged out after a few commits of > 100
>>>> docs.
>>>>
>>>> All that said, there have been a LOT of improvements since 4.6, so it
>>>> might
>>>> be something that's been addressed in the intervening time.
>>>>
>>>> Best,
>>>> Erick
>>>>
>>>>
>>>>
>>>> On Wed, Oct 7, 2015 at 7:39 PM, Rallavagu <ra...@gmail.com> wrote:
>>>>>
>>>>>
>>>>> Solr 4.6.1, single shard, 4 node cloud, 3 node zk
>>>>>
>>>>> Like to understand the behavior better when large number of updates
>>>>> happen
>>>>> on leader and it generates huge tlog (14G sometimes in my case) on
>>>>> other
>>>>> nodes. At the same time leader's tlog is few KB. So, what is the rate
>>>>> at
>>>>> which the changes from transaction log are applied at nodes? The
>>>>> autocommit
>>>>> interval is set to 15 seconds after going through
>>>>>
>>>>>
>>>>> https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
>>>>>
>>>>> Thanks
Re: tlog replay
Posted by Rallavagu <ra...@gmail.com>.
As a follow up.
Eventually the tlog file is disappeared (could not track the time it
took to clear out completely). However, following messages were noticed
in follower's log.
5120638 [recoveryExecutor-14-thread-2] WARN
org.apache.solr.update.UpdateLog – Starting log replay tlog
On 10/7/15 8:29 PM, Erick Erickson wrote:
> The only way I can account for such a large file off the top of my
> head is if, for some reason,
> the Solr on the node somehow was failing to index documents and kept
> adding them to the
> log for a loooonnngggg time. But how that would happen without the
> node being in recovery
> mode I'm not sure. I mean the Solr instance would have to be healthy
> otherwise but just not
> able to index docs which makes no sense.
>
> The usual question here is whether there were any messages in the solr
> log file indicating
> problems while this built up.
>
> tlogs will build up to very large sizes if there are very long hard
> commit intervals, but I don't
> see how that interval would be different on the leader and follower.
>
> So color me puzzled.
>
> Best,
> Erick
>
> On Wed, Oct 7, 2015 at 8:09 PM, Rallavagu <ra...@gmail.com> wrote:
>> Thanks Erick.
>>
>> Eventually, followers caught up but the 14G tlog file still persists and
>> they are healthy. Is there anything to look for? Will monitor and see how
>> long will it take before it disappears.
>>
>> Evaluating move to Solr 5.3.
>>
>> On 10/7/15 7:51 PM, Erick Erickson wrote:
>>>
>>> Uhm, that's very weird. Updates are not applied from the tlog. Rather the
>>> raw doc is forwarded to the replica which both indexes the doc and
>>> writes it to the local tlog. So having a 14G tlog on a follower but a
>>> small
>>> tlog on the leader is definitely strange, especially if it persists over
>>> time.
>>>
>>> I assume the follower is healthy? And does this very large tlog disappear
>>> after a while? I'd expect it to be aged out after a few commits of > 100
>>> docs.
>>>
>>> All that said, there have been a LOT of improvements since 4.6, so it
>>> might
>>> be something that's been addressed in the intervening time.
>>>
>>> Best,
>>> Erick
>>>
>>>
>>>
>>> On Wed, Oct 7, 2015 at 7:39 PM, Rallavagu <ra...@gmail.com> wrote:
>>>>
>>>> Solr 4.6.1, single shard, 4 node cloud, 3 node zk
>>>>
>>>> Like to understand the behavior better when large number of updates
>>>> happen
>>>> on leader and it generates huge tlog (14G sometimes in my case) on other
>>>> nodes. At the same time leader's tlog is few KB. So, what is the rate at
>>>> which the changes from transaction log are applied at nodes? The
>>>> autocommit
>>>> interval is set to 15 seconds after going through
>>>>
>>>> https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
>>>>
>>>> Thanks
Re: tlog replay
Posted by Erick Erickson <er...@gmail.com>.
The only way I can account for such a large file off the top of my
head is if, for some reason,
the Solr on the node somehow was failing to index documents and kept
adding them to the
log for a loooonnngggg time. But how that would happen without the
node being in recovery
mode I'm not sure. I mean the Solr instance would have to be healthy
otherwise but just not
able to index docs which makes no sense.
The usual question here is whether there were any messages in the solr
log file indicating
problems while this built up.
tlogs will build up to very large sizes if there are very long hard
commit intervals, but I don't
see how that interval would be different on the leader and follower.
So color me puzzled.
Best,
Erick
On Wed, Oct 7, 2015 at 8:09 PM, Rallavagu <ra...@gmail.com> wrote:
> Thanks Erick.
>
> Eventually, followers caught up but the 14G tlog file still persists and
> they are healthy. Is there anything to look for? Will monitor and see how
> long will it take before it disappears.
>
> Evaluating move to Solr 5.3.
>
> On 10/7/15 7:51 PM, Erick Erickson wrote:
>>
>> Uhm, that's very weird. Updates are not applied from the tlog. Rather the
>> raw doc is forwarded to the replica which both indexes the doc and
>> writes it to the local tlog. So having a 14G tlog on a follower but a
>> small
>> tlog on the leader is definitely strange, especially if it persists over
>> time.
>>
>> I assume the follower is healthy? And does this very large tlog disappear
>> after a while? I'd expect it to be aged out after a few commits of > 100
>> docs.
>>
>> All that said, there have been a LOT of improvements since 4.6, so it
>> might
>> be something that's been addressed in the intervening time.
>>
>> Best,
>> Erick
>>
>>
>>
>> On Wed, Oct 7, 2015 at 7:39 PM, Rallavagu <ra...@gmail.com> wrote:
>>>
>>> Solr 4.6.1, single shard, 4 node cloud, 3 node zk
>>>
>>> Like to understand the behavior better when large number of updates
>>> happen
>>> on leader and it generates huge tlog (14G sometimes in my case) on other
>>> nodes. At the same time leader's tlog is few KB. So, what is the rate at
>>> which the changes from transaction log are applied at nodes? The
>>> autocommit
>>> interval is set to 15 seconds after going through
>>>
>>> https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
>>>
>>> Thanks
Re: tlog replay
Posted by Rallavagu <ra...@gmail.com>.
Thanks Erick.
Eventually, followers caught up but the 14G tlog file still persists and
they are healthy. Is there anything to look for? Will monitor and see
how long will it take before it disappears.
Evaluating move to Solr 5.3.
On 10/7/15 7:51 PM, Erick Erickson wrote:
> Uhm, that's very weird. Updates are not applied from the tlog. Rather the
> raw doc is forwarded to the replica which both indexes the doc and
> writes it to the local tlog. So having a 14G tlog on a follower but a small
> tlog on the leader is definitely strange, especially if it persists over time.
>
> I assume the follower is healthy? And does this very large tlog disappear
> after a while? I'd expect it to be aged out after a few commits of > 100 docs.
>
> All that said, there have been a LOT of improvements since 4.6, so it might
> be something that's been addressed in the intervening time.
>
> Best,
> Erick
>
>
>
> On Wed, Oct 7, 2015 at 7:39 PM, Rallavagu <ra...@gmail.com> wrote:
>> Solr 4.6.1, single shard, 4 node cloud, 3 node zk
>>
>> Like to understand the behavior better when large number of updates happen
>> on leader and it generates huge tlog (14G sometimes in my case) on other
>> nodes. At the same time leader's tlog is few KB. So, what is the rate at
>> which the changes from transaction log are applied at nodes? The autocommit
>> interval is set to 15 seconds after going through
>> https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
>>
>> Thanks
Re: tlog replay
Posted by Erick Erickson <er...@gmail.com>.
Uhm, that's very weird. Updates are not applied from the tlog. Rather the
raw doc is forwarded to the replica which both indexes the doc and
writes it to the local tlog. So having a 14G tlog on a follower but a small
tlog on the leader is definitely strange, especially if it persists over time.
I assume the follower is healthy? And does this very large tlog disappear
after a while? I'd expect it to be aged out after a few commits of > 100 docs.
All that said, there have been a LOT of improvements since 4.6, so it might
be something that's been addressed in the intervening time.
Best,
Erick
On Wed, Oct 7, 2015 at 7:39 PM, Rallavagu <ra...@gmail.com> wrote:
> Solr 4.6.1, single shard, 4 node cloud, 3 node zk
>
> Like to understand the behavior better when large number of updates happen
> on leader and it generates huge tlog (14G sometimes in my case) on other
> nodes. At the same time leader's tlog is few KB. So, what is the rate at
> which the changes from transaction log are applied at nodes? The autocommit
> interval is set to 15 seconds after going through
> https://lucidworks.com/blog/understanding-transaction-logs-softcommit-and-commit-in-sorlcloud/
>
> Thanks