Re: Taking a long time to roll a new log segment (~1 min)
Yep, that's exactly what the output is showing. On Fri, Jan 13, 2017 at 11:25 AM, Tauzell, Dave < dave.tauz...@surescripts.com> wrote: > I haven't used dtrace, but is it possible to have it running and recording > the ftruncate64 times? Then when you see one of these long roll times look > at the dtrace log to see if it was that call? > > -Dave > > -Original Message- > From: Stephen Powis [mailto:spo...@salesforce.com] > Sent: Friday, January 13, 2017 9:25 AM > To: users@kafka.apache.org > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > So the underlying system call is ftruncate64, logged using dtrace. > > # BEGIN stack trace for ftruncate, call took 34160541200ns: > > args== > > 0x7f5f9a1134d7 : ftruncate64+0x7/0x30 [/lib64/libc-2.12.so] > > 0x7f5f987b80c3 : 0x7f5f987b80c3 > > [/usr/lib/jvm/jdk1.8.0_51/jre/lib/amd64/libjava.so+0x180c3/0x22c000] > > # END stack trace for ftruncate > > > > These index files seem to be typically around 10MB for open log segments, > and get truncated down to ~1MB after being closed. I'd imagine truncating > off ~9MB shouldn't be that heavy of an operation. > > ZFS options: > > > data/kafka type filesystem - > > data/kafka creation Tue Feb 9 22:45 2016 - > > data/kafka used 196G - > > data/kafka available 6.65T - > > data/kafka referenced196G - > > data/kafka compressratio 4.59x - > > data/kafka mounted yes- > > data/kafka quota none default > > data/kafka reservation none default > > data/kafka recordsize128K default > > data/kafka mountpoint/kafka local > > data/kafka sharenfs offdefault > > data/kafka checksum on default > > data/kafka compression lz4inherited > > from data > > data/kafka atime offinherited > > from data > > data/kafka devices on default > > data/kafka exec on default > > data/kafka setuidon default > > data/kafka readonly offdefault > > data/kafka zoned offdefault > > data/kafka snapdir hidden default > > data/kafka aclinheritrestricted default > > data/kafka canmount on default > > data/kafka xattr on default > > data/kafka copies1 default > > data/kafka version 5 - > > data/kafka utf8only off- > > data/kafka normalization none - > > data/kafka casesensitivity sensitive - > > data/kafka vscan offdefault > > data/kafka nbmandoffdefault > > data/kafka sharesmb offdefault > > data/kafka refquota none default > > data/kafka refreservationnone default > > data/kafka primarycache alldefault > > data/kafka secondarycachealldefault > > data/kafka usedbysnapshots 0 - > > data/kafka usedbydataset 196G - > > data/kafka usedbychildren0 - > > data/kafka usedbyrefreservation 0 - > > data/kafka logbias throughput local > > data/kafka dedup offdefault > > data/kafka mlslabel none default > > data/kafka sync standard default > > data/kafka refcompressratio 4.59x - > > data/kafka written 196G - > > data/kafka logicalused 900G - > > data/
RE: Taking a long time to roll a new log segment (~1 min)
I haven't used dtrace, but is it possible to have it running and recording the ftruncate64 times? Then when you see one of these long roll times look at the dtrace log to see if it was that call? -Dave -Original Message- From: Stephen Powis [mailto:spo...@salesforce.com] Sent: Friday, January 13, 2017 9:25 AM To: users@kafka.apache.org Subject: Re: Taking a long time to roll a new log segment (~1 min) So the underlying system call is ftruncate64, logged using dtrace. # BEGIN stack trace for ftruncate, call took 34160541200ns: > args== > 0x7f5f9a1134d7 : ftruncate64+0x7/0x30 [/lib64/libc-2.12.so] > 0x7f5f987b80c3 : 0x7f5f987b80c3 > [/usr/lib/jvm/jdk1.8.0_51/jre/lib/amd64/libjava.so+0x180c3/0x22c000] > # END stack trace for ftruncate > These index files seem to be typically around 10MB for open log segments, and get truncated down to ~1MB after being closed. I'd imagine truncating off ~9MB shouldn't be that heavy of an operation. ZFS options: > data/kafka type filesystem - > data/kafka creation Tue Feb 9 22:45 2016 - > data/kafka used 196G - > data/kafka available 6.65T - > data/kafka referenced196G - > data/kafka compressratio 4.59x - > data/kafka mounted yes- > data/kafka quota none default > data/kafka reservation none default > data/kafka recordsize128K default > data/kafka mountpoint/kafka local > data/kafka sharenfs offdefault > data/kafka checksum on default > data/kafka compression lz4inherited > from data > data/kafka atime offinherited > from data > data/kafka devices on default > data/kafka exec on default > data/kafka setuidon default > data/kafka readonly offdefault > data/kafka zoned offdefault > data/kafka snapdir hidden default > data/kafka aclinheritrestricted default > data/kafka canmount on default > data/kafka xattr on default data/kafka copies1 default > data/kafka version 5 - > data/kafka utf8only off- > data/kafka normalization none - > data/kafka casesensitivity sensitive - > data/kafka vscan offdefault > data/kafka nbmandoffdefault > data/kafka sharesmb offdefault > data/kafka refquota none default > data/kafka refreservationnone default > data/kafka primarycache alldefault > data/kafka secondarycachealldefault > data/kafka usedbysnapshots 0 - > data/kafka usedbydataset 196G - > data/kafka usedbychildren0 - > data/kafka usedbyrefreservation 0 - > data/kafka logbias throughput local > data/kafka dedup offdefault > data/kafka mlslabel none default > data/kafka sync standard default > data/kafka refcompressratio 4.59x - > data/kafka written 196G - > data/kafka logicalused 900G - > data/kafka logicalreferenced 900G - > data/kafka filesystem_limit none default > data/kafka snapshot_limitnone default > data/kafka filesystem_count none default > data/kafka snapshot_countnone default > data/kafka snapdev hidden default > data/kafka acltype offdefault > data/kafka co
Re: Taking a long time to roll a new log segment (~1 min)
> data/kafka overlay offdefault > CPU IO Wait is extremely low (below 0.01%) with no recorded spikes. On Fri, Jan 13, 2017 at 6:57 AM, Ismael Juma wrote: > Hi Stephen, > > I think it's worth capturing this in a JIRA so that it doesn't get lost. > > Ismael > > On Thu, Jan 12, 2017 at 7:22 PM, Stephen Powis > wrote: > > > I've further narrowed it down to this particular line: > > https://github.com/apache/kafka/blob/0.10.0/core/src/ > main/scala/kafka/log/ > > OffsetIndex.scala#L294 > > > > But I'm still at a loss to why this would be slow sometimes and not > others. > > > > On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis > > wrote: > > > > > Using the little bash script in that JIRA ticket to go thru the GC log > > and > > > sum up the total pause times I come up with the following. I don't see > > > anything that would indicate a ~28 second pause. > > > > > > 2017-01-12T07:00 = 72.2961 > > >> 2017-01-12T07:01 = 59.8112 > > >> 2017-01-12T07:02 = 69.6915 > > >> 2017-01-12T07:03 = 74.4093 > > >> 2017-01-12T07:04 = 73.507 > > >> 2017-01-12T07:05 = 73.7028 > > >> 2017-01-12T07:06 = 72.3392 > > >> 2017-01-12T07:07 = 70.502 > > >> 2017-01-12T07:08 = 71.7471 > > >> 2017-01-12T07:09 = 76.8371 > > >> 2017-01-12T07:10 = 72.3836 > > >> 2017-01-12T07:11 = 74.7462 > > >> 2017-01-12T07:12 = 57.1328 > > >> 2017-01-12T07:13 = 80.005 > > >> 2017-01-12T07:14 = 76.0012 > > >> 2017-01-12T07:15 = 79.2221 > > >> 2017-01-12T07:16 = 57.5385 > > >> 2017-01-12T07:17 = 58.1185 > > >> 2017-01-12T07:18 = 72.0524 > > >> 2017-01-12T07:19 = 110.6736 > > >> 2017-01-12T07:20 = 64.9808 > > >> 2017-01-12T07:21 = 66.8767 > > >> 2017-01-12T07:22 = 32.409 > > >> 2017-01-12T07:23 = 85.3671 > > >> 2017-01-12T07:24 = 123.9212 > > >> 2017-01-12T07:25 = 70.3219 > > >> > > > > > > > > > > > > > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > > > > wrote: > > > > > >> Just realized that GCEasy doesn't keep reports around for very long > > >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD > > >> > > >> The longest reported GC pause was 30ms, tho they happen somewhat > > >> frequently at an average of once per 12 seconds. KAFKA-4616 certainly > > >> sounds just like my scenario, but I'm having trouble finding the long > GC > > >> pauses described in that ticket in my own logs. > > >> > > >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao > > wrote: > > >> > > >>> You may run into this bug https://issues.apache.org/jira > > >>> /browse/KAFKA-4614 > > >>> > > >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis > > >>> wrote: > > >>> > > >>> > Per my email to the list in Sept, when I reviewed GC logs then, I > > >>> didn't > > >>> > see anything out of the ordinary. ( > > >>> > > > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. > > >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% > > >>> 40mail.gmail.com%3E > > >>> > ) > > >>> > > > >>> > Reviewing the GC logs from this morning around the timestamp in my > > >>> previous > > >>> > email, I see GC running roughly every 10-12 seconds, with total > times > > >>> > similar to the following: > > >>> > > > >>> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which > > >>> application > > >>> > > threads were stopped: 0.0141281 seconds, Stopping threads took: > > >>> 0.0002171 > > >>> > > seconds > > >>> > > > > >>> > > > > >>> > Here is a link to a GCEasy report: > > >>> > > > >>> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv > > >>> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= > > >>> > > > >>> > > > >>> > Currently using G1 gc with the following settings: > > >>> > > > >>> &
Re: Taking a long time to roll a new log segment (~1 min)
Hi Stephen, I think it's worth capturing this in a JIRA so that it doesn't get lost. Ismael On Thu, Jan 12, 2017 at 7:22 PM, Stephen Powis wrote: > I've further narrowed it down to this particular line: > https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/ > OffsetIndex.scala#L294 > > But I'm still at a loss to why this would be slow sometimes and not others. > > On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis > wrote: > > > Using the little bash script in that JIRA ticket to go thru the GC log > and > > sum up the total pause times I come up with the following. I don't see > > anything that would indicate a ~28 second pause. > > > > 2017-01-12T07:00 = 72.2961 > >> 2017-01-12T07:01 = 59.8112 > >> 2017-01-12T07:02 = 69.6915 > >> 2017-01-12T07:03 = 74.4093 > >> 2017-01-12T07:04 = 73.507 > >> 2017-01-12T07:05 = 73.7028 > >> 2017-01-12T07:06 = 72.3392 > >> 2017-01-12T07:07 = 70.502 > >> 2017-01-12T07:08 = 71.7471 > >> 2017-01-12T07:09 = 76.8371 > >> 2017-01-12T07:10 = 72.3836 > >> 2017-01-12T07:11 = 74.7462 > >> 2017-01-12T07:12 = 57.1328 > >> 2017-01-12T07:13 = 80.005 > >> 2017-01-12T07:14 = 76.0012 > >> 2017-01-12T07:15 = 79.2221 > >> 2017-01-12T07:16 = 57.5385 > >> 2017-01-12T07:17 = 58.1185 > >> 2017-01-12T07:18 = 72.0524 > >> 2017-01-12T07:19 = 110.6736 > >> 2017-01-12T07:20 = 64.9808 > >> 2017-01-12T07:21 = 66.8767 > >> 2017-01-12T07:22 = 32.409 > >> 2017-01-12T07:23 = 85.3671 > >> 2017-01-12T07:24 = 123.9212 > >> 2017-01-12T07:25 = 70.3219 > >> > > > > > > > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > > wrote: > > > >> Just realized that GCEasy doesn't keep reports around for very long > >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD > >> > >> The longest reported GC pause was 30ms, tho they happen somewhat > >> frequently at an average of once per 12 seconds. KAFKA-4616 certainly > >> sounds just like my scenario, but I'm having trouble finding the long GC > >> pauses described in that ticket in my own logs. > >> > >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao > wrote: > >> > >>> You may run into this bug https://issues.apache.org/jira > >>> /browse/KAFKA-4614 > >>> > >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis > >>> wrote: > >>> > >>> > Per my email to the list in Sept, when I reviewed GC logs then, I > >>> didn't > >>> > see anything out of the ordinary. ( > >>> > > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. > >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% > >>> 40mail.gmail.com%3E > >>> > ) > >>> > > >>> > Reviewing the GC logs from this morning around the timestamp in my > >>> previous > >>> > email, I see GC running roughly every 10-12 seconds, with total times > >>> > similar to the following: > >>> > > >>> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which > >>> application > >>> > > threads were stopped: 0.0141281 seconds, Stopping threads took: > >>> 0.0002171 > >>> > > seconds > >>> > > > >>> > > > >>> > Here is a link to a GCEasy report: > >>> > > >>> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv > >>> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= > >>> > > >>> > > >>> > Currently using G1 gc with the following settings: > >>> > > >>> > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc > >>> > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps > >>> -XX:+PrintGCDetails > >>> > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime > >>> > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation > >>> > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M > -XX:+UseCompressedOops > >>> > -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:MaxGCPauseMillis=20 > >>> > -XX:+HeapDumpOnOutOfMemoryError > >>> > -XX:HeapDumpPath=/var/log/kafka/heapDump.log > >>> > -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log &
Re: Taking a long time to roll a new log segment (~1 min)
That line is truncating a file. If the underlying implementation is synchronous, it could potentially require multiple disk writes to remove blocks from the file, update the list of free blocks, etc. That could potentially cause the latency. I'm not sure that's actually where the cost is coming from, but definitely a possible explanation for the latency appearing on that specific line. -Ewen On Thu, Jan 12, 2017 at 5:33 PM, Stephane Maarek < steph...@simplemachines.com.au> wrote: > Hi Stephen > > Out of curiosity, why did you pick ZFS over XFS or ext4 and what options > are you using when formatting and mounting? > > Regards, > Stephane > > On 13 January 2017 at 6:40:18 am, Stephen Powis (spo...@salesforce.com) > wrote: > > Running Centos 6.7 3.10.95-1.el6.elrepo.x86_64. 4 SATA disks in RAID10 > with ZFS > > On Thu, Jan 12, 2017 at 2:27 PM, Tauzell, Dave < > dave.tauz...@surescripts.com > > wrote: > > > You have a local filesystem? Linux? > > > > -Dave > > > > -Original Message- > > From: Stephen Powis [mailto:spo...@salesforce.com] > > Sent: Thursday, January 12, 2017 1:22 PM > > To: users@kafka.apache.org > > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > > > I've further narrowed it down to this particular line: > > https://github.com/apache/kafka/blob/0.10.0/core/src/main/ > scala/kafka/log/ > > OffsetIndex.scala#L294 > > > > But I'm still at a loss to why this would be slow sometimes and not > others. > > > > On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis > > wrote: > > > > > Using the little bash script in that JIRA ticket to go thru the GC log > > > and sum up the total pause times I come up with the following. I > > > don't see anything that would indicate a ~28 second pause. > > > > > > 2017-01-12T07:00 = 72.2961 > > >> 2017-01-12T07:01 = 59.8112 > > >> 2017-01-12T07:02 = 69.6915 > > >> 2017-01-12T07:03 = 74.4093 > > >> 2017-01-12T07:04 = 73.507 > > >> 2017-01-12T07:05 = 73.7028 > > >> 2017-01-12T07:06 = 72.3392 > > >> 2017-01-12T07:07 = 70.502 > > >> 2017-01-12T07:08 = 71.7471 > > >> 2017-01-12T07:09 = 76.8371 > > >> 2017-01-12T07:10 = 72.3836 > > >> 2017-01-12T07:11 = 74.7462 > > >> 2017-01-12T07:12 = 57.1328 > > >> 2017-01-12T07:13 = 80.005 > > >> 2017-01-12T07:14 = 76.0012 > > >> 2017-01-12T07:15 = 79.2221 > > >> 2017-01-12T07:16 = 57.5385 > > >> 2017-01-12T07:17 = 58.1185 > > >> 2017-01-12T07:18 = 72.0524 > > >> 2017-01-12T07:19 = 110.6736 > > >> 2017-01-12T07:20 = 64.9808 > > >> 2017-01-12T07:21 = 66.8767 > > >> 2017-01-12T07:22 = 32.409 > > >> 2017-01-12T07:23 = 85.3671 > > >> 2017-01-12T07:24 = 123.9212 > > >> 2017-01-12T07:25 = 70.3219 > > >> > > > > > > > > > > > > > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > > > > > > wrote: > > > > > >> Just realized that GCEasy doesn't keep reports around for very long > > >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD > > >> > > >> The longest reported GC pause was 30ms, tho they happen somewhat > > >> frequently at an average of once per 12 seconds. KAFKA-4616 > > >> certainly sounds just like my scenario, but I'm having trouble > > >> finding the long GC pauses described in that ticket in my own logs. > > >> > > >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao > > wrote: > > >> > > >>> You may run into this bug https://issues.apache.org/jira > > >>> /browse/KAFKA-4614 > > >>> > > >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis > > >>> wrote: > > >>> > > >>> > Per my email to the list in Sept, when I reviewed GC logs then, I > > >>> didn't > > >>> > see anything out of the ordinary. ( > > >>> > > > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. > > >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% > > >>> 40mail.gmail.com%3E > > >>> > ) > > >>> > > > >>> > Reviewing the GC logs from this morning around the timestamp in my > > >>> previous > > >>> > email
Re: Taking a long time to roll a new log segment (~1 min)
Hi Stephen Out of curiosity, why did you pick ZFS over XFS or ext4 and what options are you using when formatting and mounting? Regards, Stephane On 13 January 2017 at 6:40:18 am, Stephen Powis (spo...@salesforce.com) wrote: Running Centos 6.7 3.10.95-1.el6.elrepo.x86_64. 4 SATA disks in RAID10 with ZFS On Thu, Jan 12, 2017 at 2:27 PM, Tauzell, Dave wrote: > You have a local filesystem? Linux? > > -Dave > > -Original Message- > From: Stephen Powis [mailto:spo...@salesforce.com] > Sent: Thursday, January 12, 2017 1:22 PM > To: users@kafka.apache.org > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > I've further narrowed it down to this particular line: > https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/ > OffsetIndex.scala#L294 > > But I'm still at a loss to why this would be slow sometimes and not others. > > On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis > wrote: > > > Using the little bash script in that JIRA ticket to go thru the GC log > > and sum up the total pause times I come up with the following. I > > don't see anything that would indicate a ~28 second pause. > > > > 2017-01-12T07:00 = 72.2961 > >> 2017-01-12T07:01 = 59.8112 > >> 2017-01-12T07:02 = 69.6915 > >> 2017-01-12T07:03 = 74.4093 > >> 2017-01-12T07:04 = 73.507 > >> 2017-01-12T07:05 = 73.7028 > >> 2017-01-12T07:06 = 72.3392 > >> 2017-01-12T07:07 = 70.502 > >> 2017-01-12T07:08 = 71.7471 > >> 2017-01-12T07:09 = 76.8371 > >> 2017-01-12T07:10 = 72.3836 > >> 2017-01-12T07:11 = 74.7462 > >> 2017-01-12T07:12 = 57.1328 > >> 2017-01-12T07:13 = 80.005 > >> 2017-01-12T07:14 = 76.0012 > >> 2017-01-12T07:15 = 79.2221 > >> 2017-01-12T07:16 = 57.5385 > >> 2017-01-12T07:17 = 58.1185 > >> 2017-01-12T07:18 = 72.0524 > >> 2017-01-12T07:19 = 110.6736 > >> 2017-01-12T07:20 = 64.9808 > >> 2017-01-12T07:21 = 66.8767 > >> 2017-01-12T07:22 = 32.409 > >> 2017-01-12T07:23 = 85.3671 > >> 2017-01-12T07:24 = 123.9212 > >> 2017-01-12T07:25 = 70.3219 > >> > > > > > > > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > > > > wrote: > > > >> Just realized that GCEasy doesn't keep reports around for very long > >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD > >> > >> The longest reported GC pause was 30ms, tho they happen somewhat > >> frequently at an average of once per 12 seconds. KAFKA-4616 > >> certainly sounds just like my scenario, but I'm having trouble > >> finding the long GC pauses described in that ticket in my own logs. > >> > >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao > wrote: > >> > >>> You may run into this bug https://issues.apache.org/jira > >>> /browse/KAFKA-4614 > >>> > >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis > >>> wrote: > >>> > >>> > Per my email to the list in Sept, when I reviewed GC logs then, I > >>> didn't > >>> > see anything out of the ordinary. ( > >>> > > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. > >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% > >>> 40mail.gmail.com%3E > >>> > ) > >>> > > >>> > Reviewing the GC logs from this morning around the timestamp in my > >>> previous > >>> > email, I see GC running roughly every 10-12 seconds, with total > >>> > times similar to the following: > >>> > > >>> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which > >>> application > >>> > > threads were stopped: 0.0141281 seconds, Stopping threads took: > >>> 0.0002171 > >>> > > seconds > >>> > > > >>> > > > >>> > Here is a link to a GCEasy report: > >>> > > >>> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv > >>> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= > >>> > > >>> > > >>> > Currently using G1 gc with the following settings: > >>> > > >>> > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc > >>> > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps > >>> -XX:+PrintGCDetails > >>> > -XX:+PrintTenuringDistribution -XX:+Print
Re: Taking a long time to roll a new log segment (~1 min)
Running Centos 6.7 3.10.95-1.el6.elrepo.x86_64. 4 SATA disks in RAID10 with ZFS On Thu, Jan 12, 2017 at 2:27 PM, Tauzell, Dave wrote: > You have a local filesystem? Linux? > > -Dave > > -Original Message- > From: Stephen Powis [mailto:spo...@salesforce.com] > Sent: Thursday, January 12, 2017 1:22 PM > To: users@kafka.apache.org > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > I've further narrowed it down to this particular line: > https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/ > OffsetIndex.scala#L294 > > But I'm still at a loss to why this would be slow sometimes and not others. > > On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis > wrote: > > > Using the little bash script in that JIRA ticket to go thru the GC log > > and sum up the total pause times I come up with the following. I > > don't see anything that would indicate a ~28 second pause. > > > > 2017-01-12T07:00 = 72.2961 > >> 2017-01-12T07:01 = 59.8112 > >> 2017-01-12T07:02 = 69.6915 > >> 2017-01-12T07:03 = 74.4093 > >> 2017-01-12T07:04 = 73.507 > >> 2017-01-12T07:05 = 73.7028 > >> 2017-01-12T07:06 = 72.3392 > >> 2017-01-12T07:07 = 70.502 > >> 2017-01-12T07:08 = 71.7471 > >> 2017-01-12T07:09 = 76.8371 > >> 2017-01-12T07:10 = 72.3836 > >> 2017-01-12T07:11 = 74.7462 > >> 2017-01-12T07:12 = 57.1328 > >> 2017-01-12T07:13 = 80.005 > >> 2017-01-12T07:14 = 76.0012 > >> 2017-01-12T07:15 = 79.2221 > >> 2017-01-12T07:16 = 57.5385 > >> 2017-01-12T07:17 = 58.1185 > >> 2017-01-12T07:18 = 72.0524 > >> 2017-01-12T07:19 = 110.6736 > >> 2017-01-12T07:20 = 64.9808 > >> 2017-01-12T07:21 = 66.8767 > >> 2017-01-12T07:22 = 32.409 > >> 2017-01-12T07:23 = 85.3671 > >> 2017-01-12T07:24 = 123.9212 > >> 2017-01-12T07:25 = 70.3219 > >> > > > > > > > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > > > > wrote: > > > >> Just realized that GCEasy doesn't keep reports around for very long > >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD > >> > >> The longest reported GC pause was 30ms, tho they happen somewhat > >> frequently at an average of once per 12 seconds. KAFKA-4616 > >> certainly sounds just like my scenario, but I'm having trouble > >> finding the long GC pauses described in that ticket in my own logs. > >> > >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao > wrote: > >> > >>> You may run into this bug https://issues.apache.org/jira > >>> /browse/KAFKA-4614 > >>> > >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis > >>> wrote: > >>> > >>> > Per my email to the list in Sept, when I reviewed GC logs then, I > >>> didn't > >>> > see anything out of the ordinary. ( > >>> > > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. > >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% > >>> 40mail.gmail.com%3E > >>> > ) > >>> > > >>> > Reviewing the GC logs from this morning around the timestamp in my > >>> previous > >>> > email, I see GC running roughly every 10-12 seconds, with total > >>> > times similar to the following: > >>> > > >>> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which > >>> application > >>> > > threads were stopped: 0.0141281 seconds, Stopping threads took: > >>> 0.0002171 > >>> > > seconds > >>> > > > >>> > > > >>> > Here is a link to a GCEasy report: > >>> > > >>> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv > >>> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= > >>> > > >>> > > >>> > Currently using G1 gc with the following settings: > >>> > > >>> > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc > >>> > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps > >>> -XX:+PrintGCDetails > >>> > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime > >>> > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation > >>> > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M > >>> > -XX:+UseCompresse
RE: Taking a long time to roll a new log segment (~1 min)
You have a local filesystem? Linux? -Dave -Original Message- From: Stephen Powis [mailto:spo...@salesforce.com] Sent: Thursday, January 12, 2017 1:22 PM To: users@kafka.apache.org Subject: Re: Taking a long time to roll a new log segment (~1 min) I've further narrowed it down to this particular line: https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/OffsetIndex.scala#L294 But I'm still at a loss to why this would be slow sometimes and not others. On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis wrote: > Using the little bash script in that JIRA ticket to go thru the GC log > and sum up the total pause times I come up with the following. I > don't see anything that would indicate a ~28 second pause. > > 2017-01-12T07:00 = 72.2961 >> 2017-01-12T07:01 = 59.8112 >> 2017-01-12T07:02 = 69.6915 >> 2017-01-12T07:03 = 74.4093 >> 2017-01-12T07:04 = 73.507 >> 2017-01-12T07:05 = 73.7028 >> 2017-01-12T07:06 = 72.3392 >> 2017-01-12T07:07 = 70.502 >> 2017-01-12T07:08 = 71.7471 >> 2017-01-12T07:09 = 76.8371 >> 2017-01-12T07:10 = 72.3836 >> 2017-01-12T07:11 = 74.7462 >> 2017-01-12T07:12 = 57.1328 >> 2017-01-12T07:13 = 80.005 >> 2017-01-12T07:14 = 76.0012 >> 2017-01-12T07:15 = 79.2221 >> 2017-01-12T07:16 = 57.5385 >> 2017-01-12T07:17 = 58.1185 >> 2017-01-12T07:18 = 72.0524 >> 2017-01-12T07:19 = 110.6736 >> 2017-01-12T07:20 = 64.9808 >> 2017-01-12T07:21 = 66.8767 >> 2017-01-12T07:22 = 32.409 >> 2017-01-12T07:23 = 85.3671 >> 2017-01-12T07:24 = 123.9212 >> 2017-01-12T07:25 = 70.3219 >> > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > > wrote: > >> Just realized that GCEasy doesn't keep reports around for very long >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD >> >> The longest reported GC pause was 30ms, tho they happen somewhat >> frequently at an average of once per 12 seconds. KAFKA-4616 >> certainly sounds just like my scenario, but I'm having trouble >> finding the long GC pauses described in that ticket in my own logs. >> >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao wrote: >> >>> You may run into this bug https://issues.apache.org/jira >>> /browse/KAFKA-4614 >>> >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis >>> wrote: >>> >>> > Per my email to the list in Sept, when I reviewed GC logs then, I >>> didn't >>> > see anything out of the ordinary. ( >>> > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% >>> 40mail.gmail.com%3E >>> > ) >>> > >>> > Reviewing the GC logs from this morning around the timestamp in my >>> previous >>> > email, I see GC running roughly every 10-12 seconds, with total >>> > times similar to the following: >>> > >>> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which >>> application >>> > > threads were stopped: 0.0141281 seconds, Stopping threads took: >>> 0.0002171 >>> > > seconds >>> > > >>> > > >>> > Here is a link to a GCEasy report: >>> > >>> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv >>> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= >>> > >>> > >>> > Currently using G1 gc with the following settings: >>> > >>> > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc >>> > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps >>> -XX:+PrintGCDetails >>> > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime >>> > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation >>> > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M >>> > -XX:+UseCompressedOops -XX:+AlwaysPreTouch -XX:+UseG1GC >>> > -XX:MaxGCPauseMillis=20 -XX:+HeapDumpOnOutOfMemoryError >>> > -XX:HeapDumpPath=/var/log/kafka/heapDump.log >>> > -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log >>> > -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps >>> > -XX:+PrintGCTimeStamps >>> > >>> > >>> > >>> > On Thu, Jan 12, 2017 at 9:55 AM, Tauzell, Dave < >>> > dave.tauz...@surescripts.com >>> > > wrote: >>> > >>> > > Can you collect garbage collection stats and verify there isn't >&g
Re: Taking a long time to roll a new log segment (~1 min)
I've further narrowed it down to this particular line: https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/OffsetIndex.scala#L294 But I'm still at a loss to why this would be slow sometimes and not others. On Thu, Jan 12, 2017 at 10:56 AM, Stephen Powis wrote: > Using the little bash script in that JIRA ticket to go thru the GC log and > sum up the total pause times I come up with the following. I don't see > anything that would indicate a ~28 second pause. > > 2017-01-12T07:00 = 72.2961 >> 2017-01-12T07:01 = 59.8112 >> 2017-01-12T07:02 = 69.6915 >> 2017-01-12T07:03 = 74.4093 >> 2017-01-12T07:04 = 73.507 >> 2017-01-12T07:05 = 73.7028 >> 2017-01-12T07:06 = 72.3392 >> 2017-01-12T07:07 = 70.502 >> 2017-01-12T07:08 = 71.7471 >> 2017-01-12T07:09 = 76.8371 >> 2017-01-12T07:10 = 72.3836 >> 2017-01-12T07:11 = 74.7462 >> 2017-01-12T07:12 = 57.1328 >> 2017-01-12T07:13 = 80.005 >> 2017-01-12T07:14 = 76.0012 >> 2017-01-12T07:15 = 79.2221 >> 2017-01-12T07:16 = 57.5385 >> 2017-01-12T07:17 = 58.1185 >> 2017-01-12T07:18 = 72.0524 >> 2017-01-12T07:19 = 110.6736 >> 2017-01-12T07:20 = 64.9808 >> 2017-01-12T07:21 = 66.8767 >> 2017-01-12T07:22 = 32.409 >> 2017-01-12T07:23 = 85.3671 >> 2017-01-12T07:24 = 123.9212 >> 2017-01-12T07:25 = 70.3219 >> > > > > > > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis > wrote: > >> Just realized that GCEasy doesn't keep reports around for very long >> anymore, here is a screencap of the report: http://imgur.com/a/MEubD >> >> The longest reported GC pause was 30ms, tho they happen somewhat >> frequently at an average of once per 12 seconds. KAFKA-4616 certainly >> sounds just like my scenario, but I'm having trouble finding the long GC >> pauses described in that ticket in my own logs. >> >> On Thu, Jan 12, 2017 at 10:42 AM, tao xiao wrote: >> >>> You may run into this bug https://issues.apache.org/jira >>> /browse/KAFKA-4614 >>> >>> On Thu, 12 Jan 2017 at 23:38 Stephen Powis >>> wrote: >>> >>> > Per my email to the list in Sept, when I reviewed GC logs then, I >>> didn't >>> > see anything out of the ordinary. ( >>> > >>> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. >>> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% >>> 40mail.gmail.com%3E >>> > ) >>> > >>> > Reviewing the GC logs from this morning around the timestamp in my >>> previous >>> > email, I see GC running roughly every 10-12 seconds, with total times >>> > similar to the following: >>> > >>> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which >>> application >>> > > threads were stopped: 0.0141281 seconds, Stopping threads took: >>> 0.0002171 >>> > > seconds >>> > > >>> > > >>> > Here is a link to a GCEasy report: >>> > >>> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv >>> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= >>> > >>> > >>> > Currently using G1 gc with the following settings: >>> > >>> > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc >>> > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps >>> -XX:+PrintGCDetails >>> > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime >>> > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation >>> > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -XX:+UseCompressedOops >>> > -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:MaxGCPauseMillis=20 >>> > -XX:+HeapDumpOnOutOfMemoryError >>> > -XX:HeapDumpPath=/var/log/kafka/heapDump.log >>> > -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log -verbose:gc >>> > -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps >>> > >>> > >>> > >>> > On Thu, Jan 12, 2017 at 9:55 AM, Tauzell, Dave < >>> > dave.tauz...@surescripts.com >>> > > wrote: >>> > >>> > > Can you collect garbage collection stats and verify there isn't a >>> long GC >>> > > happening at the same time? >>> > > >>> > > -Dave >>> > > >>> > > -Original Message- >>> > > From: Stephen Powis [mailto:spo...@salesforce.com] >>> > > S
Re: Taking a long time to roll a new log segment (~1 min)
Using the little bash script in that JIRA ticket to go thru the GC log and sum up the total pause times I come up with the following. I don't see anything that would indicate a ~28 second pause. 2017-01-12T07:00 = 72.2961 > 2017-01-12T07:01 = 59.8112 > 2017-01-12T07:02 = 69.6915 > 2017-01-12T07:03 = 74.4093 > 2017-01-12T07:04 = 73.507 > 2017-01-12T07:05 = 73.7028 > 2017-01-12T07:06 = 72.3392 > 2017-01-12T07:07 = 70.502 > 2017-01-12T07:08 = 71.7471 > 2017-01-12T07:09 = 76.8371 > 2017-01-12T07:10 = 72.3836 > 2017-01-12T07:11 = 74.7462 > 2017-01-12T07:12 = 57.1328 > 2017-01-12T07:13 = 80.005 > 2017-01-12T07:14 = 76.0012 > 2017-01-12T07:15 = 79.2221 > 2017-01-12T07:16 = 57.5385 > 2017-01-12T07:17 = 58.1185 > 2017-01-12T07:18 = 72.0524 > 2017-01-12T07:19 = 110.6736 > 2017-01-12T07:20 = 64.9808 > 2017-01-12T07:21 = 66.8767 > 2017-01-12T07:22 = 32.409 > 2017-01-12T07:23 = 85.3671 > 2017-01-12T07:24 = 123.9212 > 2017-01-12T07:25 = 70.3219 > On Thu, Jan 12, 2017 at 10:49 AM, Stephen Powis wrote: > Just realized that GCEasy doesn't keep reports around for very long > anymore, here is a screencap of the report: http://imgur.com/a/MEubD > > The longest reported GC pause was 30ms, tho they happen somewhat > frequently at an average of once per 12 seconds. KAFKA-4616 certainly > sounds just like my scenario, but I'm having trouble finding the long GC > pauses described in that ticket in my own logs. > > On Thu, Jan 12, 2017 at 10:42 AM, tao xiao wrote: > >> You may run into this bug https://issues.apache.org/jira >> /browse/KAFKA-4614 >> >> On Thu, 12 Jan 2017 at 23:38 Stephen Powis wrote: >> >> > Per my email to the list in Sept, when I reviewed GC logs then, I didn't >> > see anything out of the ordinary. ( >> > >> > http://mail-archives.apache.org/mod_mbox/kafka-users/201609. >> mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ% >> 40mail.gmail.com%3E >> > ) >> > >> > Reviewing the GC logs from this morning around the timestamp in my >> previous >> > email, I see GC running roughly every 10-12 seconds, with total times >> > similar to the following: >> > >> > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which >> application >> > > threads were stopped: 0.0141281 seconds, Stopping threads took: >> 0.0002171 >> > > seconds >> > > >> > > >> > Here is a link to a GCEasy report: >> > >> > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIv >> LS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= >> > >> > >> > Currently using G1 gc with the following settings: >> > >> > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc >> > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps -XX:+PrintGCDetails >> > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime >> > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation >> > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -XX:+UseCompressedOops >> > -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:MaxGCPauseMillis=20 >> > -XX:+HeapDumpOnOutOfMemoryError >> > -XX:HeapDumpPath=/var/log/kafka/heapDump.log >> > -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log -verbose:gc >> > -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps >> > >> > >> > >> > On Thu, Jan 12, 2017 at 9:55 AM, Tauzell, Dave < >> > dave.tauz...@surescripts.com >> > > wrote: >> > >> > > Can you collect garbage collection stats and verify there isn't a >> long GC >> > > happening at the same time? >> > > >> > > -Dave >> > > >> > > -Original Message- >> > > From: Stephen Powis [mailto:spo...@salesforce.com] >> > > Sent: Thursday, January 12, 2017 8:34 AM >> > > To: users@kafka.apache.org >> > > Subject: Re: Taking a long time to roll a new log segment (~1 min) >> > > >> > > So per the kafka docs I up'd our FD limit to 100k, and we are no >> longer >> > > seeing the process die, which is good. >> > > >> > > Unfortunately we're still seeing very high log segment roll times, and >> > I'm >> > > unsure if this is considered 'normal', as it tends to block producers >> > > during this period. >> > > >> > > We are running kafka 0.10.0.1, but I patched in some additionally >> timing >> > > state
Re: Taking a long time to roll a new log segment (~1 min)
Just realized that GCEasy doesn't keep reports around for very long anymore, here is a screencap of the report: http://imgur.com/a/MEubD The longest reported GC pause was 30ms, tho they happen somewhat frequently at an average of once per 12 seconds. KAFKA-4616 certainly sounds just like my scenario, but I'm having trouble finding the long GC pauses described in that ticket in my own logs. On Thu, Jan 12, 2017 at 10:42 AM, tao xiao wrote: > You may run into this bug https://issues.apache.org/jira/browse/KAFKA-4614 > > On Thu, 12 Jan 2017 at 23:38 Stephen Powis wrote: > > > Per my email to the list in Sept, when I reviewed GC logs then, I didn't > > see anything out of the ordinary. ( > > > > http://mail-archives.apache.org/mod_mbox/kafka-users/ > 201609.mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz > 0kCjmdB9c0SDcLQ%40mail.gmail.com%3E > > ) > > > > Reviewing the GC logs from this morning around the timestamp in my > previous > > email, I see GC running roughly every 10-12 seconds, with total times > > similar to the following: > > > > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which application > > > threads were stopped: 0.0141281 seconds, Stopping threads took: > 0.0002171 > > > seconds > > > > > > > > Here is a link to a GCEasy report: > > > > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIvLS10b3 > RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= > > > > > > Currently using G1 gc with the following settings: > > > > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc > > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps -XX:+PrintGCDetails > > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime > > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation > > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -XX:+UseCompressedOops > > -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:MaxGCPauseMillis=20 > > -XX:+HeapDumpOnOutOfMemoryError > > -XX:HeapDumpPath=/var/log/kafka/heapDump.log > > -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log -verbose:gc > > -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps > > > > > > > > On Thu, Jan 12, 2017 at 9:55 AM, Tauzell, Dave < > > dave.tauz...@surescripts.com > > > wrote: > > > > > Can you collect garbage collection stats and verify there isn't a long > GC > > > happening at the same time? > > > > > > -Dave > > > > > > -Original Message- > > > From: Stephen Powis [mailto:spo...@salesforce.com] > > > Sent: Thursday, January 12, 2017 8:34 AM > > > To: users@kafka.apache.org > > > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > > > > > So per the kafka docs I up'd our FD limit to 100k, and we are no longer > > > seeing the process die, which is good. > > > > > > Unfortunately we're still seeing very high log segment roll times, and > > I'm > > > unsure if this is considered 'normal', as it tends to block producers > > > during this period. > > > > > > We are running kafka 0.10.0.1, but I patched in some additionally > timing > > > statements into the kafka.log.log roll() method to narrow down exactly > > > which part of that method is taking so long. > > > > > > Again, typically the process to roll a new log file takes only 1-2ms > > tops, > > > but several times a day it takes 30-60+ seconds, across all of our > > > brokers. I've narrowed it down to this bit of code causing the issue: > > > https://github.com/apache/kafka/blob/0.10.0/core/src/ > > > main/scala/kafka/log/Log.scala#L652-L658 > > > > > > Here's an example of output w/ my additional timing log statements: > > > > > > [2017-01-12 07:17:58,199] INFO Rolled new log segment for 'MyTopic-4' > in > > > > 28028 ms. (kafka.log.Log) > > > > > > [2017-01-12 07:17:58,200] INFO LastEntry match time 'EventStream-4' in > > > > 28027 ms. (kafka.log.Log) > > > > > > > > > > Any thoughts? Help? This considered normal? > > > > > > Thanks > > > Stephen > > > > > > > > > On Tue, Jan 10, 2017 at 2:37 AM, Ewen Cheslack-Postava < > > e...@confluent.io> > > > wrote: > > > > > > > I can't speak to the exact details of why fds would be kept open > > > > longer in that specific case, but are you aware that
Re: Taking a long time to roll a new log segment (~1 min)
You may run into this bug https://issues.apache.org/jira/browse/KAFKA-4614 On Thu, 12 Jan 2017 at 23:38 Stephen Powis wrote: > Per my email to the list in Sept, when I reviewed GC logs then, I didn't > see anything out of the ordinary. ( > > http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ%40mail.gmail.com%3E > ) > > Reviewing the GC logs from this morning around the timestamp in my previous > email, I see GC running roughly every 10-12 seconds, with total times > similar to the following: > > 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which application > > threads were stopped: 0.0141281 seconds, Stopping threads took: 0.0002171 > > seconds > > > > > Here is a link to a GCEasy report: > > http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIvLS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= > > > Currently using G1 gc with the following settings: > > -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc > -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps -XX:+PrintGCDetails > -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime > -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation > -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -XX:+UseCompressedOops > -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:MaxGCPauseMillis=20 > -XX:+HeapDumpOnOutOfMemoryError > -XX:HeapDumpPath=/var/log/kafka/heapDump.log > -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log -verbose:gc > -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps > > > > On Thu, Jan 12, 2017 at 9:55 AM, Tauzell, Dave < > dave.tauz...@surescripts.com > > wrote: > > > Can you collect garbage collection stats and verify there isn't a long GC > > happening at the same time? > > > > -Dave > > > > -----Original Message----- > > From: Stephen Powis [mailto:spo...@salesforce.com] > > Sent: Thursday, January 12, 2017 8:34 AM > > To: users@kafka.apache.org > > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > > > So per the kafka docs I up'd our FD limit to 100k, and we are no longer > > seeing the process die, which is good. > > > > Unfortunately we're still seeing very high log segment roll times, and > I'm > > unsure if this is considered 'normal', as it tends to block producers > > during this period. > > > > We are running kafka 0.10.0.1, but I patched in some additionally timing > > statements into the kafka.log.log roll() method to narrow down exactly > > which part of that method is taking so long. > > > > Again, typically the process to roll a new log file takes only 1-2ms > tops, > > but several times a day it takes 30-60+ seconds, across all of our > > brokers. I've narrowed it down to this bit of code causing the issue: > > https://github.com/apache/kafka/blob/0.10.0/core/src/ > > main/scala/kafka/log/Log.scala#L652-L658 > > > > Here's an example of output w/ my additional timing log statements: > > > > [2017-01-12 07:17:58,199] INFO Rolled new log segment for 'MyTopic-4' in > > > 28028 ms. (kafka.log.Log) > > > > [2017-01-12 07:17:58,200] INFO LastEntry match time 'EventStream-4' in > > > 28027 ms. (kafka.log.Log) > > > > > > > Any thoughts? Help? This considered normal? > > > > Thanks > > Stephen > > > > > > On Tue, Jan 10, 2017 at 2:37 AM, Ewen Cheslack-Postava < > e...@confluent.io> > > wrote: > > > > > I can't speak to the exact details of why fds would be kept open > > > longer in that specific case, but are you aware that the > > > recommendation for production clusters for open fd limits is much > > > higher? It's been suggested to be 100,000 as a starting point for quite > > awhile: > > > http://kafka.apache.org/documentation.html#os > > > > > > -Ewen > > > > > > On Mon, Jan 9, 2017 at 12:45 PM, Stephen Powis > > > wrote: > > > > > > > Hey! > > > > > > > > I've run into something concerning in our production clusterI > > > > believe I've posted this question to the mailing list previously ( > > > > http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/bro > > > > wser > > > ) > > > > but the problem has become considerably more serious. > > > > > > > > We've been fighting issues where Kafka 0.10.0.1 hits its max file > > > >
Re: Taking a long time to roll a new log segment (~1 min)
Per my email to the list in Sept, when I reviewed GC logs then, I didn't see anything out of the ordinary. ( http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/%3CCABQB-gS7h4Nuq3TKgHoAVeRHPWnBNs2B0Tz0kCjmdB9c0SDcLQ%40mail.gmail.com%3E ) Reviewing the GC logs from this morning around the timestamp in my previous email, I see GC running roughly every 10-12 seconds, with total times similar to the following: 2017-01-12T07:16:46.867-0500: 46891.844: Total time for which application > threads were stopped: 0.0141281 seconds, Stopping threads took: 0.0002171 > seconds > > Here is a link to a GCEasy report: http://gceasy.io/my-gc-report.jsp?p=c2hhcmVkLzIwMTcvMDEvMTIvLS10b3RhbEdDLWthZmthMS00LmxvZy5nei0tMTUtMzQtNTk= Currently using G1 gc with the following settings: -Xmx12G -Xms12G -server -XX:MaxPermSize=48M -verbose:gc -Xloggc:/var/log/kafka/gc.log -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintTenuringDistribution -XX:+PrintGCApplicationStoppedTime -XX:+PrintTLAB -XX:+DisableExplicitGC -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=10 -XX:GCLogFileSize=100M -XX:+UseCompressedOops -XX:+AlwaysPreTouch -XX:+UseG1GC -XX:MaxGCPauseMillis=20 -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/var/log/kafka/heapDump.log -Xloggc:/opt/kafka/current/bin/../logs/kafkaServer-gc.log -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+PrintGCTimeStamps On Thu, Jan 12, 2017 at 9:55 AM, Tauzell, Dave wrote: > Can you collect garbage collection stats and verify there isn't a long GC > happening at the same time? > > -Dave > > -Original Message- > From: Stephen Powis [mailto:spo...@salesforce.com] > Sent: Thursday, January 12, 2017 8:34 AM > To: users@kafka.apache.org > Subject: Re: Taking a long time to roll a new log segment (~1 min) > > So per the kafka docs I up'd our FD limit to 100k, and we are no longer > seeing the process die, which is good. > > Unfortunately we're still seeing very high log segment roll times, and I'm > unsure if this is considered 'normal', as it tends to block producers > during this period. > > We are running kafka 0.10.0.1, but I patched in some additionally timing > statements into the kafka.log.log roll() method to narrow down exactly > which part of that method is taking so long. > > Again, typically the process to roll a new log file takes only 1-2ms tops, > but several times a day it takes 30-60+ seconds, across all of our > brokers. I've narrowed it down to this bit of code causing the issue: > https://github.com/apache/kafka/blob/0.10.0/core/src/ > main/scala/kafka/log/Log.scala#L652-L658 > > Here's an example of output w/ my additional timing log statements: > > [2017-01-12 07:17:58,199] INFO Rolled new log segment for 'MyTopic-4' in > > 28028 ms. (kafka.log.Log) > > [2017-01-12 07:17:58,200] INFO LastEntry match time 'EventStream-4' in > > 28027 ms. (kafka.log.Log) > > > > Any thoughts? Help? This considered normal? > > Thanks > Stephen > > > On Tue, Jan 10, 2017 at 2:37 AM, Ewen Cheslack-Postava > wrote: > > > I can't speak to the exact details of why fds would be kept open > > longer in that specific case, but are you aware that the > > recommendation for production clusters for open fd limits is much > > higher? It's been suggested to be 100,000 as a starting point for quite > awhile: > > http://kafka.apache.org/documentation.html#os > > > > -Ewen > > > > On Mon, Jan 9, 2017 at 12:45 PM, Stephen Powis > > wrote: > > > > > Hey! > > > > > > I've run into something concerning in our production clusterI > > > believe I've posted this question to the mailing list previously ( > > > http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/bro > > > wser > > ) > > > but the problem has become considerably more serious. > > > > > > We've been fighting issues where Kafka 0.10.0.1 hits its max file > > > descriptor limit. Our limit is set to ~16k, and under normal > > > operation > > it > > > holds steady around 4k open files. > > > > > > But occasionally Kafka will roll a new log segment, which typically > > > takes on the order of magnitude of a few milliseconds. > > > However...sometimes it will take a considerable amount of time, any > > > where from 40 seconds up to over a minute. When this happens, it > > > seems like connections are not released by kafka, and we end up with > > > thousands of client connections > > stuck > > > in CLOSE_WAIT, which pile up and exceed our max file descriptor limit. > > > This ha
RE: Taking a long time to roll a new log segment (~1 min)
Can you collect garbage collection stats and verify there isn't a long GC happening at the same time? -Dave -Original Message- From: Stephen Powis [mailto:spo...@salesforce.com] Sent: Thursday, January 12, 2017 8:34 AM To: users@kafka.apache.org Subject: Re: Taking a long time to roll a new log segment (~1 min) So per the kafka docs I up'd our FD limit to 100k, and we are no longer seeing the process die, which is good. Unfortunately we're still seeing very high log segment roll times, and I'm unsure if this is considered 'normal', as it tends to block producers during this period. We are running kafka 0.10.0.1, but I patched in some additionally timing statements into the kafka.log.log roll() method to narrow down exactly which part of that method is taking so long. Again, typically the process to roll a new log file takes only 1-2ms tops, but several times a day it takes 30-60+ seconds, across all of our brokers. I've narrowed it down to this bit of code causing the issue: https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/Log.scala#L652-L658 Here's an example of output w/ my additional timing log statements: [2017-01-12 07:17:58,199] INFO Rolled new log segment for 'MyTopic-4' in > 28028 ms. (kafka.log.Log) [2017-01-12 07:17:58,200] INFO LastEntry match time 'EventStream-4' in > 28027 ms. (kafka.log.Log) > Any thoughts? Help? This considered normal? Thanks Stephen On Tue, Jan 10, 2017 at 2:37 AM, Ewen Cheslack-Postava wrote: > I can't speak to the exact details of why fds would be kept open > longer in that specific case, but are you aware that the > recommendation for production clusters for open fd limits is much > higher? It's been suggested to be 100,000 as a starting point for quite > awhile: > http://kafka.apache.org/documentation.html#os > > -Ewen > > On Mon, Jan 9, 2017 at 12:45 PM, Stephen Powis > wrote: > > > Hey! > > > > I've run into something concerning in our production clusterI > > believe I've posted this question to the mailing list previously ( > > http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/bro > > wser > ) > > but the problem has become considerably more serious. > > > > We've been fighting issues where Kafka 0.10.0.1 hits its max file > > descriptor limit. Our limit is set to ~16k, and under normal > > operation > it > > holds steady around 4k open files. > > > > But occasionally Kafka will roll a new log segment, which typically > > takes on the order of magnitude of a few milliseconds. > > However...sometimes it will take a considerable amount of time, any > > where from 40 seconds up to over a minute. When this happens, it > > seems like connections are not released by kafka, and we end up with > > thousands of client connections > stuck > > in CLOSE_WAIT, which pile up and exceed our max file descriptor limit. > > This happens all in the span of about a minute. > > > > Our logs look like this: > > > > [2017-01-08 01:10:17,117] INFO Rolled new log segment for > > 'MyTopic-8' in > > > 41122 ms. (kafka.log.Log) > > > [2017-01-08 01:10:32,550] INFO Rolled new log segment for 'MyTopic-4' > in > > 1 > > > ms. (kafka.log.Log) > > > [2017-01-08 01:11:10,039] INFO [Group Metadata Manager on Broker 4]: > > > Removed 0 expired offsets in 0 milliseconds. > > > (kafka.coordinator.GroupMetadataManager) > > > [2017-01-08 01:19:02,877] ERROR Error while accepting connection > > > (kafka.network.Acceptor) > > > java.io.IOException: Too many open files at > > > sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) > > > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 422) > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 250) > > > at kafka.network.Acceptor.accept(SocketServer.scala:323) > > > at kafka.network.Acceptor.run(SocketServer.scala:268) > > > at java.lang.Thread.run(Thread.java:745) > > > [2017-01-08 01:19:02,877] ERROR Error while accepting connection > > > (kafka.network.Acceptor) > > > java.io.IOException: Too many open files > > > at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 422) > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketCha
Re: Taking a long time to roll a new log segment (~1 min)
So per the kafka docs I up'd our FD limit to 100k, and we are no longer seeing the process die, which is good. Unfortunately we're still seeing very high log segment roll times, and I'm unsure if this is considered 'normal', as it tends to block producers during this period. We are running kafka 0.10.0.1, but I patched in some additionally timing statements into the kafka.log.log roll() method to narrow down exactly which part of that method is taking so long. Again, typically the process to roll a new log file takes only 1-2ms tops, but several times a day it takes 30-60+ seconds, across all of our brokers. I've narrowed it down to this bit of code causing the issue: https://github.com/apache/kafka/blob/0.10.0/core/src/main/scala/kafka/log/Log.scala#L652-L658 Here's an example of output w/ my additional timing log statements: [2017-01-12 07:17:58,199] INFO Rolled new log segment for 'MyTopic-4' in > 28028 ms. (kafka.log.Log) [2017-01-12 07:17:58,200] INFO LastEntry match time 'EventStream-4' in > 28027 ms. (kafka.log.Log) > Any thoughts? Help? This considered normal? Thanks Stephen On Tue, Jan 10, 2017 at 2:37 AM, Ewen Cheslack-Postava wrote: > I can't speak to the exact details of why fds would be kept open longer in > that specific case, but are you aware that the recommendation for > production clusters for open fd limits is much higher? It's been suggested > to be 100,000 as a starting point for quite awhile: > http://kafka.apache.org/documentation.html#os > > -Ewen > > On Mon, Jan 9, 2017 at 12:45 PM, Stephen Powis > wrote: > > > Hey! > > > > I've run into something concerning in our production clusterI believe > > I've posted this question to the mailing list previously ( > > http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/browser > ) > > but the problem has become considerably more serious. > > > > We've been fighting issues where Kafka 0.10.0.1 hits its max file > > descriptor limit. Our limit is set to ~16k, and under normal operation > it > > holds steady around 4k open files. > > > > But occasionally Kafka will roll a new log segment, which typically takes > > on the order of magnitude of a few milliseconds. However...sometimes it > > will take a considerable amount of time, any where from 40 seconds up to > > over a minute. When this happens, it seems like connections are not > > released by kafka, and we end up with thousands of client connections > stuck > > in CLOSE_WAIT, which pile up and exceed our max file descriptor limit. > > This happens all in the span of about a minute. > > > > Our logs look like this: > > > > [2017-01-08 01:10:17,117] INFO Rolled new log segment for 'MyTopic-8' in > > > 41122 ms. (kafka.log.Log) > > > [2017-01-08 01:10:32,550] INFO Rolled new log segment for 'MyTopic-4' > in > > 1 > > > ms. (kafka.log.Log) > > > [2017-01-08 01:11:10,039] INFO [Group Metadata Manager on Broker 4]: > > > Removed 0 expired offsets in 0 milliseconds. > > > (kafka.coordinator.GroupMetadataManager) > > > [2017-01-08 01:19:02,877] ERROR Error while accepting connection > > > (kafka.network.Acceptor) > > > java.io.IOException: Too many open files at > > > sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) > > > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 422) > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 250) > > > at kafka.network.Acceptor.accept(SocketServer.scala:323) > > > at kafka.network.Acceptor.run(SocketServer.scala:268) > > > at java.lang.Thread.run(Thread.java:745) > > > [2017-01-08 01:19:02,877] ERROR Error while accepting connection > > > (kafka.network.Acceptor) > > > java.io.IOException: Too many open files > > > at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 422) > > > at > > > sun.nio.ch.ServerSocketChannelImpl.accept( > ServerSocketChannelImpl.java: > > 250) > > > at kafka.network.Acceptor.accept(SocketServer.scala:323) > > > at kafka.network.Acceptor.run(SocketServer.scala:268) > > > at java.lang.Thread.run(Thread.java:745) > > > . > > > > > > > > > And then kafka crashes. > > > > Has anyone seen this behavior of slow log segmented being rolled? Any > > ideas of how to track down what could be causing this? > > > > Thanks! > > Stephen > > >
Re: Taking a long time to roll a new log segment (~1 min)
I can't speak to the exact details of why fds would be kept open longer in that specific case, but are you aware that the recommendation for production clusters for open fd limits is much higher? It's been suggested to be 100,000 as a starting point for quite awhile: http://kafka.apache.org/documentation.html#os -Ewen On Mon, Jan 9, 2017 at 12:45 PM, Stephen Powis wrote: > Hey! > > I've run into something concerning in our production clusterI believe > I've posted this question to the mailing list previously ( > http://mail-archives.apache.org/mod_mbox/kafka-users/201609.mbox/browser) > but the problem has become considerably more serious. > > We've been fighting issues where Kafka 0.10.0.1 hits its max file > descriptor limit. Our limit is set to ~16k, and under normal operation it > holds steady around 4k open files. > > But occasionally Kafka will roll a new log segment, which typically takes > on the order of magnitude of a few milliseconds. However...sometimes it > will take a considerable amount of time, any where from 40 seconds up to > over a minute. When this happens, it seems like connections are not > released by kafka, and we end up with thousands of client connections stuck > in CLOSE_WAIT, which pile up and exceed our max file descriptor limit. > This happens all in the span of about a minute. > > Our logs look like this: > > [2017-01-08 01:10:17,117] INFO Rolled new log segment for 'MyTopic-8' in > > 41122 ms. (kafka.log.Log) > > [2017-01-08 01:10:32,550] INFO Rolled new log segment for 'MyTopic-4' in > 1 > > ms. (kafka.log.Log) > > [2017-01-08 01:11:10,039] INFO [Group Metadata Manager on Broker 4]: > > Removed 0 expired offsets in 0 milliseconds. > > (kafka.coordinator.GroupMetadataManager) > > [2017-01-08 01:19:02,877] ERROR Error while accepting connection > > (kafka.network.Acceptor) > > java.io.IOException: Too many open files at > > sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) > > > at > > sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java: > 422) > > at > > sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java: > 250) > > at kafka.network.Acceptor.accept(SocketServer.scala:323) > > at kafka.network.Acceptor.run(SocketServer.scala:268) > > at java.lang.Thread.run(Thread.java:745) > > [2017-01-08 01:19:02,877] ERROR Error while accepting connection > > (kafka.network.Acceptor) > > java.io.IOException: Too many open files > > at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method) > > at > > sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java: > 422) > > at > > sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java: > 250) > > at kafka.network.Acceptor.accept(SocketServer.scala:323) > > at kafka.network.Acceptor.run(SocketServer.scala:268) > > at java.lang.Thread.run(Thread.java:745) > > . > > > > > And then kafka crashes. > > Has anyone seen this behavior of slow log segmented being rolled? Any > ideas of how to track down what could be causing this? > > Thanks! > Stephen >
