Can back pressure data be gathered by Flink metric system?

[徐涛]

Hi Experts,

From the page Flink metric system(https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/metrics.html#system-metrics), I do not find the info about the back pressure. I want to get the backpressure data and plot it, but I do not know how to get it via metric. 

Can anybody help me about it? Thanks a lot.

Best

Henry

[Zhijiang(wangzhijiang999)]

Hi Henry,

The backpressure tracking is not realized in metric framework, you could check the details via [1]. I am not sure why your requirements is showing backpressure in metrics.

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/back_pressure.html

Best,

Zhijiang

 ------------------------------------------------------------------

From:徐涛 <[hidden email]>

Send Time:2019年4月15日(星期一) 10:19

To:user <[hidden email]>

Subject:Can back pressure data be gathered by Flink metric system?

Hi Experts,

From the page Flink metric system(https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/metrics.html#system-metrics), I do not find the info about the back pressure. I want to get the backpressure data and plot it, but I do not know how to get it via metric. 

Can anybody help me about it? Thanks a lot.

Best

Henry

[Biao Liu]

Hi Henry,

I have just checked the back pressure relevant codes. It is indeed not included in metric system.

As a workaround way, you can manually trigger the back pressure tracking through RESTful API (see details in [1]) periodically. And plot with the data returned.

BTW I think it's a reasonable requirement. Maybe you could start a discussion in dev mailing list.

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/rest_api.html#jobs-jobid-vertices-vertexid-backpressure

zhijiang <[hidden email]> 于2019年4月15日周一 上午10:34写道：

Hi Henry,

The backpressure tracking is not realized in metric framework, you could check the details via [1]. I am not sure why your requirements is showing backpressure in metrics.

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/back_pressure.html

Best,

Zhijiang

 ------------------------------------------------------------------

From:徐涛 <[hidden email]>

Send Time:2019年4月15日(星期一) 10:19

To:user <[hidden email]>

Subject:Can back pressure data be gathered by Flink metric system?

Hi Experts,

From the page Flink metric system(https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/metrics.html#system-metrics), I do not find the info about the back pressure. I want to get the backpressure data and plot it, but I do not know how to get it via metric. 

Can anybody help me about it? Thanks a lot.

Best

Henry

[徐涛]

Hi Zhijiang,

Because I want to know the current and the trend of backpressure status in Flink Job. Like other index such as latency, I can monitor it, and show it in graph by getting data from metric. Now using the metric to get the backpressure data is the simplest way I can think.

Best

Henry

在 2019年4月15日，上午10:34，zhijiang <[hidden email]> 写道：

Hi Henry,

The backpressure tracking is not realized in metric framework, you could check the details via [1]. I am not sure why your requirements is showing backpressure in metrics.

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/back_pressure.html

Best,

Zhijiang

 ------------------------------------------------------------------

From:徐涛 <[hidden email]>

Send Time:2019年4月15日(星期一) 10:19

To:user <[hidden email]>

Subject:Can back pressure data be gathered by Flink metric system?

Hi Experts,

From the page Flink metric system(https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/metrics.html#system-metrics), I do not find the info about the back pressure. I want to get the backpressure data and plot it, but I do not know how to get it via metric. 

Can anybody help me about it? Thanks a lot.

Best

Henry

[Zhijiang(wangzhijiang999)]

Hi Henry,

Thanks for the explanation. I am not sure whether it is feasible on your side to monitor the backpressure via restful api provided by flink.

Some experience on my side to share. We ever monitored the backpressure via the metrics of outqueue length/usage on producer side and inqueue length/usage on consumer side. Although it is not very accurate sometimes, it could provide some hints of backpressure, because the outqueue and inqueue should be filled with buffers between producer and consumer when backpressure occurs.

Best,

Zhijiang

------------------------------------------------------------------

From:徐涛 <[hidden email]>

Send Time:2019年4月16日(星期二) 09:33

To:zhijiang <[hidden email]>

Cc:user <[hidden email]>

Subject:Re: Can back pressure data be gathered by Flink metric system?

Hi Zhijiang,

Because I want to know the current and the trend of backpressure status in Flink Job. Like other index such as latency, I can monitor it, and show it in graph by getting data from metric. Now using the metric to get the backpressure data is the simplest way I can think.

Best

Henry

在 2019年4月15日，上午10:34，zhijiang <[hidden email]> 写道：

Hi Henry,

The backpressure tracking is not realized in metric framework, you could check the details via [1]. I am not sure why your requirements is showing backpressure in metrics.

[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/back_pressure.html

Best,

Zhijiang

 ------------------------------------------------------------------

From:徐涛 <[hidden email]>

Send Time:2019年4月15日(星期一) 10:19

To:user <[hidden email]>

Subject:Can back pressure data be gathered by Flink metric system?

Hi Experts,

From the page Flink metric system(https://ci.apache.org/projects/flink/flink-docs-release-1.8/monitoring/metrics.html#system-metrics), I do not find the info about the back pressure. I want to get the backpressure data and plot it, but I do not know how to get it via metric. 

Can anybody help me about it? Thanks a lot.

Best

Henry