Meaning of checkpointStartDelayNanos

[Kai Fu]

Hi team,

I'm a little confused by the meaning of checkpointStartDelayNanos, I do not understand what time it exactly means, but it seems it's a quite important indicator for checkpoint/backpresure.  The explanation of it on metrics page does not help too much. Can someone help to explain it more clearly?

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[Kai Fu]

I found its meaning in the code. It means the delay of checkpoint action when the checkpoint barrier comes to the current operator since it's intiated in the source.

On Mon, Apr 5, 2021 at 9:21 AM Kai Fu <[hidden email]> wrote:

Hi team,

I'm a little confused by the meaning of checkpointStartDelayNanos, I do not understand what time it exactly means, but it seems it's a quite important indicator for checkpoint/backpresure.  The explanation of it on metrics page does not help too much. Can someone help to explain it more clearly?

--

Best regards,

- Kai

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[Yun Gao]

Hi Kai,

Yes, you are basically right, one minor point is that the start time is

taken as the time that the checkpoint get intiated in the JM side.

Best,

 Yun

------------------Original Mail ------------------

Sender:Kai Fu <[hidden email]>

Send Date:Mon Apr 5 09:31:58 2021

Recipients:user <[hidden email]>

Subject:Re: Meaning of checkpointStartDelayNanos

I found its meaning in the code. It means the delay of checkpoint action when the checkpoint barrier comes to the current operator since it's intiated in the source.

On Mon, Apr 5, 2021 at 9:21 AM Kai Fu <[hidden email]> wrote:

Hi team,

I'm a little confused by the meaning of checkpointStartDelayNanos, I do not understand what time it exactly means, but it seems it's a quite important indicator for checkpoint/backpresure.  The explanation of it on metrics page does not help too much. Can someone help to explain it more clearly?

--

Best regards,

- Kai

--

[Kai Fu]

Thank you for the clarification Yun, it helps.

-- Best wishes

Kai

On Mon, Apr 5, 2021 at 12:03 PM Yun Gao <[hidden email]> wrote:

Hi Kai,

Yes, you are basically right, one minor point is that the start time is

taken as the time that the checkpoint get intiated in the JM side.

Best,

 Yun

------------------Original Mail ------------------

Sender:Kai Fu <[hidden email]>

Send Date:Mon Apr 5 09:31:58 2021

Recipients:user <[hidden email]>

Subject:Re: Meaning of checkpointStartDelayNanos

I found its meaning in the code. It means the delay of checkpoint action when the checkpoint barrier comes to the current operator since it's intiated in the source.

On Mon, Apr 5, 2021 at 9:21 AM Kai Fu <[hidden email]> wrote:

Hi team,

I'm a little confused by the meaning of checkpointStartDelayNanos, I do not understand what time it exactly means, but it seems it's a quite important indicator for checkpoint/backpresure.  The explanation of it on metrics page does not help too much. Can someone help to explain it more clearly?

--

Best regards,

- Kai

--

Best regards,

- Kai

--

Best regards,

- Kai