Re: Implementing CheckpointableInputFormat

[Lu Niu <qq...@gmail.com>]

Hi, Fabian

Thanks for replying!

I implemented a Custom RichInputFormat
implementing CheckpointableInputFormat. And I found it is executed
through InputFormatSourceFunction, which doesn't
use CheckpointableInputFormat during execution. If so, how does checkpoint
work here?

I also notice when one task finished, I cannot trigger savepoint anymore.
It throws exception "Not all tasks are running". Does that imply no
savepoint/checkpoint can be taken once any task finish?

Best
Lu

On Fri, Sep 6, 2019 at 6:33 AM Fabian Hueske <fh...@gmail.com> wrote:

> Hi,
>
> CheckpointableInputFormat is only relevant if you plan to use the
> InputFormat in a MonitoringFileSource, i.e., in a streaming application.
> If you plan to use it in a DataSet (batch) program, InputFormat is fine.
>
> Btw. the latest release Flink 1.9.0 has major improvements for the
> recovery of batch jobs.
>
> Best, Fabian
>
> Am Do., 5. Sept. 2019 um 19:01 Uhr schrieb Lu Niu <qq...@gmail.com>:
>
>> Hi, Team
>>
>> I am implementing a custom InputFormat. Shall I
>> implement CheckpointableInputFormat interface? If I don't, does that mean
>> the whole job has to restart given only one task fails? I ask because I
>> found all InputFormat implements CheckpointableInputFormat, which makes me
>> confused. Thank you!
>>
>> Best
>> Lu
>>
>

Re: Implementing CheckpointableInputFormat

[Chesnay Schepler <ch...@apache.org>]

You have to use StreamExecutionEnvironment#createFileInput for 
implementing CheckpointableInputFormat to have any effect. This 
internally results in it being used by the MonitoringFileSource.
If you use StreamExecutionEnvironment#createInput nothing will be 
checkpointed for the source; and yes this usually means having to 
restart the entire job if an error occurs.

Checkpoints/savepoints cannot be taken if any task is no longer running, 
see FLINK-2491.

On 03/10/2019 06:38, Lu Niu wrote:
> Hi, Fabian
>
> Thanks for replying!
>
> I implemented a Custom RichInputFormat 
> implementing CheckpointableInputFormat. And I found it is executed 
> through InputFormatSourceFunction, which doesn't 
> use CheckpointableInputFormat during execution. If so, how does 
> checkpoint work here?
>
> I also notice when one task finished, I cannot trigger savepoint 
> anymore. It throws exception "Not all tasks are running". Does that 
> imply no savepoint/checkpoint can be taken once any task finish?
>
> Best
> Lu
>
> On Fri, Sep 6, 2019 at 6:33 AM Fabian Hueske <fhueske@gmail.com 
> <ma...@gmail.com>> wrote:
>
>     Hi,
>
>     CheckpointableInputFormat is only relevant if you plan to use the
>     InputFormat in a MonitoringFileSource, i.e., in a streaming
>     application.
>     If you plan to use it in a DataSet (batch) program, InputFormat is
>     fine.
>
>     Btw. the latest release Flink 1.9.0 has major improvements for the
>     recovery of batch jobs.
>
>     Best, Fabian
>
>     Am Do., 5. Sept. 2019 um 19:01 Uhr schrieb Lu Niu
>     <qqibrow@gmail.com <ma...@gmail.com>>:
>
>         Hi, Team
>
>         I am implementing a custom InputFormat. Shall I
>         implement CheckpointableInputFormat interface? If I don't,
>         does that mean the whole job has to restart given only one
>         task fails? I ask because I found all InputFormat
>         implements CheckpointableInputFormat, which makes me confused.
>         Thank you!
>
>         Best
>         Lu
>