[SPDK] for primary/secondary check

[SPDK] for primary/secondary check

[liupan1234]

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Hi All,


I have one question about multi-process.


The primary/secondary check is based the flock of /var/run/.spdkX_config. Let's see the case: when the primary crash, the flock will be released, and the secondary is still running there with shared memory. When I invoke origin primary process again, it will get flock, treat itself as primary and initialize shared memory again, which is not what I want: will cause secondary process crash.


Do you have any method for me to know if there is any secondary process running?


Great thanks
Pan

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Re: [SPDK] for primary/secondary check

[Cao, Gang]

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Hi Pan,

The short term solution is that in this case (rely on some ways from the application management to know existing secondary and no primary there), explicitly start the new process as the secondary process with the parameter --proc-type = secondary.

Will also look detailed into this issue to see how to make the changes in the code level to automatically detect and handle this situation.

Thanks,
Gang

From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of liupan1234
Sent: Thursday, December 14, 2017 12:43 PM
To: spdk(a)lists.01.org
Subject: [SPDK] for primary/secondary check

Hi All,

I have one question about multi-process.

The primary/secondary check is based the flock of /var/run/.spdkX_config. Let's see the case: when the primary crash, the flock will be released, and the secondary is still running there with shared memory. When I invoke origin primary process again, it will get flock, treat itself as primary and initialize shared memory again, which is not what I want: will cause secondary process crash.

Do you have any method for me to know if there is any secondary process running?

Great thanks
Pan




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