Re: [SPDK] Regarding collection of iostat information for application with SPDK driver.

[Sreeni (Sreenivasa) Busam (Stellus) <s.busam at stellus.com>]

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Thanks Gang. I will take a look at it.
Currently I am going to implement a shared memory interface using the application where all the statistics would be written, and another program would read from the shared memory to display the IOPS and latency data like the iostat tool for Linux does today.
I need an RPC interface from the SPDK Storage application to be exposed which can use the patch you have given. It will be helpful.
If any of you see problems in the first approach, please do let me know.

From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of Cao, Gang
Sent: Monday, November 6, 2017 5:23 PM
To: Storage Performance Development Kit <spdk(a)lists.01.org>
Subject: Re: [SPDK] Regarding collection of iostat information for application with SPDK driver.

Hi Sreeni,

We have some similar work on going and you may refer to patch https://review.gerrithub.io/#/c/375075/ to take a quick look. This is based on bdev and through existing RPC method on our applications.

Once having more ideas, it may help your work on the tool.

Thanks,
Gang

From: SPDK [mailto:spdk-bounces(a)lists.01.org] On Behalf Of Sreeni (Sreenivasa) Busam (Stellus)
Sent: Tuesday, November 7, 2017 4:56 AM
To: spdk(a)lists.01.org<mailto:spdk(a)lists.01.org>
Subject: [SPDK] Regarding collection of iostat information for application with SPDK driver.

Hello,

I am working on a tool to collect IO statistics like

1.      Read IOPS

2.      Write IOPS
and other metrics on a per process basis for SSD device and given namespace. The assumption is all the Read and Write I/O statistics and latency should be collected for a given process which may do I/O on one or more NVMe SSD devices based on a configuration file.
I am going through the lib/bdev code and trying to see where I can add the code to collect the statistics. I have spent only a few days looking into the SPDK code and new to the code.
Is this the right function, spdk_bdev_io_complete() for me to start looking into?
Please give any suggestions you have or what are the functions I should look into? Where should I investigate more to collect the I/O statistics?
I appreciate your ideas and any help in this regard.

Thanks a lot,
Sreeni

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