Not really. If you look at storm.kafka.trident.TridentKafkaEmitter code
(doEmitNewPartitionBatch API). Setting time to latest will loose impact of
ignoreZkOffsets. If ignoreZkOffsets is set to true it will still read from
latest which user will not expect to happen.
/* 103 */ if ((_config.ignoreZkOffsets) &&
(!_topologyInstanceId.equals(lastInstanceId))) {
/* 104 */ offset = KafkaUtils.getOffset(consumer, _config.topic,
partition, _config.startOffsetTime);
/* */ } else {
/* 106 */ offset = ((Long)lastMeta.get("nextOffset")).longValue();
/* */ }
/* */ } else {
/* 109 */ offset = KafkaUtils.getOffset(consumer, _config.topic,
partition, _config);
/* */ }
From: Abhishek Agarwal <[email protected]<mailto:[email protected]>>
Reply-To: "[email protected]<mailto:[email protected]>"
<[email protected]<mailto:[email protected]>>
Date: Sunday, 29 May 2016 8:32 pm
To: "[email protected]<mailto:[email protected]>"
<[email protected]<mailto:[email protected]>>
Cc: Bobby Evans <[email protected]<mailto:[email protected]>>, Narendra
Bidari <[email protected]<mailto:[email protected]>>
Subject: Re: Storm's Kafka spout is not reading latest data even with new
consumer group
does setting kafkaConfig.startOffsetTime = OffsetRequest.LatestTime() not
work?
On Sun, May 29, 2016 at 7:56 PM, Sachin Pasalkar <
[email protected]<mailto:[email protected]>> wrote:
I looked at discussion thread. It looks like user did this changes so new
consumer will start reading data from earliest offset rather than latest.
They haven’t consider below case as well if the there is changes in data &
user forgot to clear old data from kafka topic it will cause mess (If user
start with new consumer user will expect to read it from latest OR he can
set offset explicitly) Setting to earliest is more error prone in PROD.
Thoughts?
From: Sachin Pasalkar
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Reply-To:
"[email protected]<mailto:[email protected]><mailto:[email protected]>"
<
[email protected]<mailto:[email protected]><mailto:[email protected]>>
Date: Saturday, 28 May 2016 5:12 pm
To:
"[email protected]<mailto:[email protected]><mailto:[email protected]>"
<
[email protected]<mailto:[email protected]><mailto:[email protected]>>,
Bobby Evans <
[email protected]<mailto:[email protected]><mailto:[email protected]>>
Cc: Narendra Bidari
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Subject: Re: Storm's Kafka spout is not reading latest data even with new
consumer group
Thanks Bobby. I will ask on ticket.
From: Bobby Evans
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>>
Reply-To:
"[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>"
<[email protected]<mailto:[email protected]><mailto:[email protected]
><mailto:[email protected]>>, Bobby Evans
><[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>>
Date: Friday, 27 May 2016 7:45 pm
To:
"[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>"
<[email protected]<mailto:[email protected]><mailto:[email protected]
><mailto:[email protected]>>
Cc: Narendra Bidari
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>>
Subject: Re: Storm's Kafka spout is not reading latest data even with new
consumer group
Looks like it changed as a part of
https://issues.apache.org/jira/browse/STORM-563. That might be a good
place to ask.
Specifically it was pull request https://github.com/apache/storm/pull/493.
To me it looks like the code was updated to use ignoreZKOffsets instead of
forceFromStart, but I have not dug into the exact details of the change to
know what all the ramifications might have been.
- Bobby
On Thursday, May 26, 2016 10:13 PM, Sachin Pasalkar <
[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>> wrote:
Can you look at this please?
From: Sachin Pasalkar
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Reply-To:
"[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>"
<[email protected]<mailto:[email protected]>
<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Date: Thursday, 26 May 2016 9:35 pm
To:
"[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>"
<[email protected]<mailto:[email protected]>
<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Cc: Narendra Bidari
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Subject: Re: Storm's Kafka spout is not reading latest data even with new
consumer group
Can anyone look at this?
From: Sachin Pasalkar
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>>
Reply-To:
"[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>"
<[email protected]<mailto:[email protected]><mailto:[email protected]
><mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Date: Thursday, 26 May 2016 1:18 pm
To:
"[email protected]<mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>"
<[email protected]<mailto:[email protected]><mailto:[email protected]
><mailto:[email protected]><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>>>
Cc: Narendra Bidari
<[email protected]<mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]><mailto:
[email protected]<mailto:[email protected]>><mailto:[email protected]>>
Subject: Storm's Kafka spout is not reading latest data even with new
consumer group
Currently if you give the latest consumer group it starts reading data
from earliest offset rather than latest
In KafkaConfig
public long startOffsetTime = OffsetRequest.EarliestTime();
In doEmitNewPartitionBatch API of storm.kafka.trident.TridentKafkaEmitter,
if consumer group is null calls goes to 109 line
if (lastMeta != null) {
/* 98 */ String lastInstanceId = null;
/* 99 */ Map lastTopoMeta = (Map)lastMeta.get("topology");
/* 100 */ if (lastTopoMeta != null)
/* 101 */ lastInstanceId = (String)lastTopoMeta.get("id");
/* */ long offset;
/* 103 */ if ((_config.ignoreZkOffsets) &&
(!_topologyInstanceId.equals(lastInstanceId))) {
/* 104 */ offset = KafkaUtils.getOffset(consumer, _config.topic,
partition, _config.startOffsetTime);
/* */ } else {
/* 106 */ offset = ((Long)lastMeta.get("nextOffset")).longValue();
/* */ }
/* */ } else {
/* 109 */ offset = KafkaUtils.getOffset(consumer, _config.topic,
partition, _config);
/* */ }
Which calls below API. As you can see this call will fetch earliest data
rather than fetching latest
public static long getOffset(SimpleConsumer consumer, String topic, int
partition, KafkaConfig config)
{
long startOffsetTime = config.startOffsetTime;
return getOffset(consumer, topic, partition, startOffsetTime);
}
How it should be (It was there in previous release 0.9.x)
public static long getOffset(SimpleConsumer consumer, String topic, int
partition, KafkaConfig config) {
long startOffsetTime = kafka.api.OffsetRequest.LatestTime();
if ( config.ignoreZkOffsets) {
startOffsetTime = config.startOffsetTime;
}
return getOffset(consumer, topic, partition, startOffsetTime);
}
This code was earlier present but somehow it got removed. I tried to
search on github but didn't found history of change.
Thanks,
Sachin
--
Regards,
Abhishek Agarwal
