Hi guys,
I'm trying add test cases, but below case crashed at line "
segReopen.recover(64*1024)--> index.trimToValidSize() ", any idea for it?
Appreciate your help.
The case assume kafka suddenly crash, and need recover the last segment.
kafka.log.LogSegmentTest > testCreateWithInitFileSizeCrash FAILED
java.io.IOException: The requested operation cannot be performed on a file w
ith a user-mapped section open
at java.io.RandomAccessFile.setLength(Native Method)
at kafka.log.OffsetIndex$$anonfun$resize$1.apply(OffsetIndex.scala:292)
at kafka.log.OffsetIndex$$anonfun$resize$1.apply(OffsetIndex.scala:283)
at kafka.utils.CoreUtils$.inLock(CoreUtils.scala:288)
at kafka.log.OffsetIndex.resize(OffsetIndex.scala:283)
at kafka.log.OffsetIndex$$anonfun$trimToValidSize$1.apply$mcV$sp(OffsetI
ndex.scala:272)
at kafka.log.OffsetIndex$$anonfun$trimToValidSize$1.apply(OffsetIndex.sc
ala:272)
at kafka.log.OffsetIndex$$anonfun$trimToValidSize$1.apply(OffsetIndex.sc
ala:272)
at kafka.utils.CoreUtils$.inLock(CoreUtils.scala:288)
at kafka.log.OffsetIndex.trimToValidSize(OffsetIndex.scala:271)
at kafka.log.LogSegment.recover(LogSegment.scala:199)
at kafka.log.LogSegmentTest.testCreateWithInitFileSizeCrash(LogSegmentTe
st.scala:306)
def recover(maxMessageSize: Int): Int = {
index.truncate()
index.resize(index.maxIndexSize)
var validBytes = 0
var lastIndexEntry = 0
val iter = log.iterator(maxMessageSize)
try {
while(iter.hasNext) {
val entry = iter.next
entry.message.ensureValid()
if(validBytes - lastIndexEntry > indexIntervalBytes) {
// we need to decompress the message, if required, to get the offset
of the first uncompressed message
val startOffset =
entry.message.compressionCodec match {
case NoCompressionCodec =>
entry.offset
case _ =>
ByteBufferMessageSet.deepIterator(entry.message).next().offset
}
index.append(startOffset, validBytes)
lastIndexEntry = validBytes
}
validBytes += MessageSet.entrySize(entry.message)
}
} catch {
case e: InvalidMessageException =>
logger.warn("Found invalid messages in log segment %s at byte offset
%d: %s.".format(log.file.getAbsolutePath, validBytes, e.getMessage))
}
val truncated = log.sizeInBytes - validBytes
log.truncateTo(validBytes)
index.trimToValidSize()
truncated
}
/* create a segment with pre allocate and Crash*/
@Test
def testCreateWithInitFileSizeCrash() {
val tempDir = TestUtils.tempDir()
val seg = new LogSegment(tempDir, 40, 1, 1000, 0, SystemTime, false,
512*1024*1024, true)
val ms = messages(50, "hello", "there")
seg.append(50, ms)
val ms2 = messages(60, "alpha", "beta")
seg.append(60, ms2)
val read = seg.read(startOffset = 55, maxSize = 200, maxOffset = None)
assertEquals(ms2.toList, read.messageSet.toList)
val oldSize = seg.log.sizeInBytes()
val oldPosition = seg.log.channel.position
val oldFileSize = seg.log.file.length
assertEquals(512*1024*1024, oldFileSize)
seg.flush()
seg.log.channel.close()
seg.index.close()
val segReopen = new LogSegment(tempDir, 40, 1, 1000, 0, SystemTime, true)
segReopen.recover(64*1024)
val size = segReopen.log.sizeInBytes()
val position = segReopen.log.channel.position
val fileSize = segReopen.log.file.length
assertEquals(oldPosition, position)
assertEquals(oldSize, size)
assertEquals(size, fileSize)
}
Thanks, Honghai Chen
http://aka.ms/kafka
http://aka.ms/manifold
-----Original Message-----
From: Sriram Subramanian [mailto:srsubraman...@linkedin.com.INVALID]
Sent: Friday, April 24, 2015 12:57 AM
To: dev@kafka.apache.org
Cc: Roshan Naik
Subject: Re: [DISCUSS] KIP 20 Enable log preallocate to improve consume
performance under windows and some old Linux file system
+1
Some information on how this will be tested would be useful.
On 4/23/15 9:33 AM, "Jay Kreps" <jay.kr...@gmail.com> wrote:
>Yeah if we understand the optimal policy for a config we always want to
>set it automatically. In this case I don't think we do yet, but down
>the road that could be nice. I think for now we should consider this
>option experimental to give people a chance to try it out.
>
>-Jay
>
>On Wed, Apr 22, 2015 at 7:32 PM, Honghai Chen
><honghai.c...@microsoft.com>
>wrote:
>
>> Hi Roshan,
>> Use the 'auto' value maybe will break the rule and mess up
>> the configuration. @Jay, any thoughts?
>>
>> Thanks, Honghai Chen
>>
>> -----Original Message-----
>> From: Sriharsha Chintalapani [mailto:harsh...@fastmail.fm]
>> Sent: Thursday, April 23, 2015 6:27 AM
>> To: dev@kafka.apache.org; Roshan Naik
>> Subject: Re: [DISCUSS] KIP 20 Enable log preallocate to improve
>> consume performance under windows and some old Linux file system
>>
>> +1 (non-binding).
>>
>> --
>> Harsha
>>
>>
>> On April 22, 2015 at 2:52:12 PM, Roshan Naik (ros...@hortonworks.com)
>> wrote:
>>
>> I see that it is safe to keep it this off by default due to some
>>concerns.
>> Eventually, for settings such as this whose 'preferred' value is
>>platform specific (or based on other criteria), it might be worth
>>considering having a default value that is not a constant but an
>>'auto' value ..
>>When
>> kafka boots up it can automatically use the preferred value. Ofcourse
>>it would have to documented as to what auto means for a given platform.
>>
>> -roshan
>>
>>
>> On 4/22/15 1:21 PM, "Jakob Homan" <jgho...@gmail.com> wrote:
>>
>> >+1. This is an important performance fix for Windows-based clusters.
>> >
>> >-Jakob
>> >
>> >On 22 April 2015 at 03:25, Honghai Chen <honghai.c...@microsoft.com>
>> >wrote:
>> >> Fix the issue Sriram mentioned. Code review and jira/KIP updated.
>> >>
>> >> Below are detail description for the scenarios:
>> >> 1.If do clear shutdown, the last log file will be truncated to its
>> >>real size since the close() function of FileMessageSet will call
>>trim(),
>> >> 2.If crash, then when restart, will go through the process of
>> >>recover() and the last log file will be truncate to its real size,
>>(and
>> >>the position will be moved to end of the file) 3.When service
>> >>start and open existing file a.Will run the LogSegment constructor
>> >>which has NO parameter "preallocate", b.Then in FileMessageSet,
>> >>the "end" in FileMessageSet will be Int.MaxValue, and then
>> >>"channel.position(math.min(channel.size().toInt, end))" will make
>> >>the position be end of the file, c.If recover needed, the recover
>> >>function will truncate file to end
>>of
>> >>valid data, and also move the position to it,
>> >>
>> >> 4.When service running and need create new log segment and new
>> >>FileMessageSet
>> >>
>> >> a.If preallocate = truei.the "end" in FileMessageSet will be 0,
>> >>the file size will be "initFileSize", and then
>> >>"channel.position(math.min(channel.size().toInt, end))" will make
>> >>the position be 0,
>> >>
>> >> b.Else if preallocate = falsei.backward compatible, the "end" in
>> >>FileMessageSet will be Int.MaxValue, the file size will be "0", and
>> >>then "channel.position(math.min(channel.size().toInt, end))" will
>> >>make the position be 0,
>> >>
>> >>
>> >>
>>
>>https://cwiki.apache.org/confluence/display/KAFKA/KIP-20+-+Enable+log+
>>pre
>>
>>>>allocate+to+improve+consume+performance+under+windows+and+some+old+L
>>>>allocate+to+improve+consume+performance+under+windows+and+some+old+i
>>>>allocate+to+improve+consume+performance+under+windows+and+some+old+n
>>>>allocate+to+improve+consume+performance+under+windows+and+some+old+u
>>>>x+
>> >>file+system
>> >> https://issues.apache.org/jira/browse/KAFKA-1646
>> >> https://reviews.apache.org/r/33204/diff/2/
>> >>
>> >> Thanks, Honghai Chen
>> >> http://aka.ms/kafka
>> >> http://aka.ms/manifold
>> >>
>> >> -----Original Message-----
>> >> From: Honghai Chen
>> >> Sent: Wednesday, April 22, 2015 11:12 AM
>> >> To: dev@kafka.apache.org
>> >> Subject: RE: [DISCUSS] KIP 20 Enable log preallocate to improve
>>consume
>> >>performance under windows and some old Linux file system
>> >>
>> >> Hi Sriram,
>> >> One sentence of code missed, will update code review board and KIP
>> >>soon.
>> >> For LogSegment and FileMessageSet, must use different constructor
>> >>function for existing file and new file, then the code "
>> >>channel.position(math.min(channel.size().toInt, end)) " will make
>> >>sure the position at end of existing file.
>> >>
>> >> Thanks, Honghai Chen
>> >>
>> >> -----Original Message-----
>> >> From: Jay Kreps [mailto:jay.kr...@gmail.com]
>> >> Sent: Wednesday, April 22, 2015 5:22 AM
>> >> To: dev@kafka.apache.org
>> >> Subject: Re: [DISCUSS] KIP 20 Enable log preallocate to improve
>>consume
>> >>performance under windows and some old Linux file system
>> >>
>> >> My understanding of the patch is that clean shutdown truncates the
>>file
>> >>back to it's true size (and reallocates it on startup). Hard crash
>> >>is handled by the normal recovery which should truncate off the
>> >>empty portion of the file.
>> >>
>> >> On Tue, Apr 21, 2015 at 10:52 AM, Sriram Subramanian <
>> >>srsubraman...@linkedin.com.invalid> wrote:
>> >>
>> >>> Could you describe how recovery works in this mode? Say, we had a
>>250
>> >>> MB preallocated segment and we wrote till 50MB and crashed. Till
>>what
>> >>> point do we recover? Also, on startup, how is the append end
>> >>> pointer set even on a clean shutdown? How does the FileChannel
>> >>> end position get set to 50 MB instead of 250 MB? The existing
>> >>> code might just
>>work
>> >>> for it but explaining that would be useful.
>> >>>
>> >>> On 4/21/15 9:40 AM, "Neha Narkhede" <n...@confluent.io> wrote:
>> >>>
>> >>> >+1. I've tried this on Linux and it helps reduce the spikes in
>>append
>> >>> >+(and
>> >>> >hence producer) latency for high throughput writes. I am not
>>entirely
>> >>> >sure why but my suspicion is that in the absence of
>> >>> >preallocation, you see spikes writes need to happen faster than
>> >>> >the time it takes Linux to allocate the next block to the file.
>> >>> >
>> >>> >It will be great to see some performance test results too.
>> >>> >
>> >>> >On Tue, Apr 21, 2015 at 9:23 AM, Jay Kreps <jay.kr...@gmail.com>
>> >>>wrote:
>> >>> >
>> >>> >> I'm also +1 on this. The change is quite small and may
>> >>> >>actually help perf on Linux as well (we've never tried this).
>> >>> >>
>> >>> >> I have a lot of concerns on testing the various failure
>>conditions
>> >>> >> but I think since it will be off by default the risk is not
>> >>> >> too
>> >>>high.
>> >>> >>
>> >>> >> -Jay
>> >>> >>
>> >>> >> On Mon, Apr 20, 2015 at 6:58 PM, Honghai Chen
>> >>> >><honghai.c...@microsoft.com>
>> >>> >> wrote:
>> >>> >>
>> >>> >> > I wrote a KIP for this after some discussion on KAFKA-1646.
>> >>> >> > https://issues.apache.org/jira/browse/KAFKA-1646
>> >>> >> >
>> >>> >> >
>> >>> >>
>> >>> >>
>> >>>
>>https://cwiki.apache.org/confluence/display/KAFKA/KIP-20+-+Enable+log+
>> >>> pre
>> >>>
>>
>>>>>>>allocate+to+improve+consume+performance+under+windows+and+some+old+L
>>>>>>>in
>> >>>>>ux+
>> >>> >>file+system
>> >>> >> > The RB is here: https://reviews.apache.org/r/33204/diff/
>> >>> >> >
>> >>> >> > Thanks, Honghai
>> >>> >> >
>> >>> >> >
>> >>> >>
>> >>> >
>> >>> >
>> >>> >
>> >>> >--
>> >>> >Thanks,
>> >>> >Neha
>> >>>
>> >>>
>>
>>
