checkpoint recovery behavior when kafka source is set to start from timestamp

["Yan Zhou [FDS Science]" <yz...@coupang.com>]

Hi Experts,


In my application, the kafka source is set to start from a specified timestamp, by calling method FlinkKafkaConsumer010#setStartFromTimestamp(long startupOffsetsTimestamp).


If the application have run a while and then recover from a checkpoint because of failure, what's the offset will the kafka source to read from? I suppose it will read from the offset that has been committed before the failure. Is it right?


I am going to verify it, however some clarification is good in case my test result doesn't meet my assumption.


Best

Yan

Re: checkpoint recovery behavior when kafka source is set to start from timestamp

["Yan Zhou [FDS Science]" <yz...@coupang.com>]

Thank you Vino. It is very helpful.

________________________________
From: vino yang <ya...@gmail.com>
Sent: Tuesday, August 7, 2018 7:22:50 PM
To: Yan Zhou [FDS Science]
Cc: user
Subject: Re: checkpoint recovery behavior when kafka source is set to start from timestamp

Hi Yan Zhou:

I think the java doc of the setStartFromTimestamp method has been explained very clearly, posted here:

/**
* Specify the consumer to start reading partitions from a specified timestamp.
* The specified timestamp must be before the current timestamp.
* This lets the consumer ignore any committed group offsets in Zookeeper / Kafka brokers.
*
* <p>The consumer will look up the earliest offset whose timestamp is greater than or equal
* to the specific timestamp from Kafka. If there's no such offset, the consumer will use the
* latest offset to read data from kafka.
*
* <p>This method does not affect where partitions are read from when the consumer is restored
* from a checkpoint or savepoint. When the consumer is restored from a checkpoint or
* savepoint, only the offsets in the restored state will be used.
*
* @param startupOffsetsTimestamp timestamp for the startup offsets, as milliseconds from epoch.
*
* @return The consumer object, to allow function chaining.
*/

Thanks, vino.

Yan Zhou [FDS Science] <yz...@coupang.com>> 于2018年8月8日周三 上午9:06写道：

Hi Experts,


In my application, the kafka source is set to start from a specified timestamp, by calling method FlinkKafkaConsumer010#setStartFromTimestamp(long startupOffsetsTimestamp).


If the application have run a while and then recover from a checkpoint because of failure, what's the offset will the kafka source to read from? I suppose it will read from the offset that has been committed before the failure. Is it right?


I am going to verify it, however some clarification is good in case my test result doesn't meet my assumption.


Best

Yan

Re: checkpoint recovery behavior when kafka source is set to start from timestamp

[vino yang <ya...@gmail.com>]

Hi Yan Zhou:

I think the java doc of the setStartFromTimestamp method has been explained
very clearly, posted here:

*/***
** Specify the consumer to start reading partitions from a specified
timestamp.*
** The specified timestamp must be before the current timestamp.*
** This lets the consumer ignore any committed group offsets in Zookeeper /
Kafka brokers.*
***
** <p>The consumer will look up the earliest offset whose timestamp is
greater than or equal*
** to the specific timestamp from Kafka. If there's no such offset, the
consumer will use the*
** latest offset to read data from kafka.*
***
** <p>This method does not affect where partitions are read from when the
consumer is restored*
** from a checkpoint or savepoint. When the consumer is restored from a
checkpoint or*
** savepoint, only the offsets in the restored state will be used.*
***
** @param startupOffsetsTimestamp timestamp for the startup offsets, as
milliseconds from epoch.*
***
** @return The consumer object, to allow function chaining.*
**/*

Thanks, vino.

Yan Zhou [FDS Science] <yz...@coupang.com> 于2018年8月8日周三 上午9:06写道：

> Hi Experts,
>
>
> In my application, the kafka source is set to start from a specified
> timestamp, by calling method FlinkKafkaConsumer010#setStartFromTimestamp(long
> startupOffsetsTimestamp).
>
>
> If the application have run a while and then recover from a checkpoint
> because of failure, what's the offset will the kafka source to read from? I
> suppose it will read from the offset that has been committed before the
> failure. Is it right?
>
>
> I am going to verify it, however some clarification is good in case my
> test result doesn't meet my assumption.
>
>
> Best
>
> Yan
>
>
>