Arup Malakar created KAFKA-1110:
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Summary: Unable to produce messages with snappy/gzip compression
Key: KAFKA-1110
URL: https://issues.apache.org/jira/browse/KAFKA-1110
Project: Kafka
Issue Type: Bug
Affects Versions: 0.8
Environment: Kafka version: kafka-0.8.0-beta1
OS version: Darwin 12.4.1 Darwin Kernel Version 12.4.1: Tue May 21 17:04:50 PDT
2013; root:xnu-2050.40.51~1/RELEASE_X86_64 x86_64
Reporter: Arup Malakar
Sarama[1] (A golang kafka library: https://github.com/Shopify/sarama) is
following the specs as defined in:
https://cwiki.apache.org/confluence/display/KAFKA/A+Guide+To+The+Kafka+Protocol
but messages are not getting into the kafka log file and consumers never see
them when gzip/snappy is used. Without compression it works fine though.
Few observations we made:
1. Kafka service does have required jars to be able to interpret snappy
messages. When I modify ConsoleProducer to produce messages using
SnappyCompressionCodec instead of default GZip codec. I was able to
produce/consume messages. Looking at the kafka log files I see that Snappy
Compression was indeed getting used:
% bin/kafka-run-class.sh kafka.tools.DumpLogSegments --files
/tmp/kafka-logs/aruptest-0/00000000000000000000.log | tail -1
offset: 15 position: 18763 isvalid: true payloadsize: 52 magic: 0
compresscodec: SnappyCompressionCodec crc: 1602790249
So I don't think it would be a case of missing jars in kafka server.
2. Kafka doesn't return any error if the message doesn't make it to the log
file. This seems pretty serious, as I would expect kafka to throw an error if I
am using WaitForLocal/WaitForAll.
3. We did an inspection of the tcp packet to see the difference between what
ConsoleProducer sends vs what sarama sends
(Following is a copy/paste from a github issue):
[~eapache] :
So I have no idea what the ConsoleProducer is actually sending in this case.
The outer protocol layers in both cases look identical, but if you compare the
actual message value:
a. Sarama sends two bytes of snappy header and then "<msg-payload>" (since
Snappy decides it's too short to properly encode, so makes it a literal).
Pretty straightforward.
b. ConsoleProducer sends 0x82 then the string literal SNAPPY\0 then what
appears to be a complete embedded produce request without any compression. This
is neither valid snappy nor valid Kafka according to anything I've seen, so I'm
pretty confused. It looks almost like an incorrect version of [1] but it's
missing several key fields and the case of the identifying string is wrong.
Let us know if recent changes in the codebase makes the protocol page obsolete,
in that case if the protocol page is updated we could update our client to use
the new spec.
More information could be found in the following github issue:
https://github.com/Shopify/sarama/issues/32
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