[EXTERNAL] Re: FreeBSD10 Stable + ZFS + PostgreSQL + SSD performance drop < 24 hours

[Caza, Aaron]

In prior testing I completely removed PostgreSQL from the equation by creating a 16GB random file on the pertinent ZFS filesystem and reading after reboot and later after the performance degradation hits.  Read performance goes from ~865MB/s with 95-100% busy in gstat down to ~61MB/s with ~10% busy.

It's not Postgres.

-----Original Message-----
From: owner-freebsd-hackers at freebsd.org [mailto:owner-freebsd-hackers at freebsd.org] On Behalf Of Eduardo Morras via freebsd-hackers
Sent: Tuesday, June 13, 2017 12:36 PM
To: freebsd-hackers at freebsd.org
Subject: Re: [EXTERNAL] Re: FreeBSD10 Stable + ZFS + PostgreSQL + SSD performance drop < 24 hours

On Mon, 12 Jun 2017 04:50:44 +0000
"Caza, Aaron" <Aaron.Caza at ca.weatherford.com> wrote:

> Thanks, Jov, for you suggestions.  Per your e-mail I added ?explain
> analyze? to the script:

Can you check that autovacuum is not involved in a lock storm?
Autovacuums workers start to work but a higher level lock is acquired by other process/transaction stopping autovacuum workers continuously, making autovacuum useless (but trying continually to clean).

Also, you're comparing Postgresql 9.1 with 9.5, are you using the same conf file? Did you upgrade it (conf file) to 9.5?

---   ---
Eduardo Morras <emorrasg at yahoo.es>
_______________________________________________
freebsd-hackers at freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-hackers
To unsubscribe, send any mail to "freebsd-hackers-unsubscribe at freebsd.org"

This message may contain confidential and privileged information. If it has been sent to you in error, please reply to advise the sender of the error and then immediately delete it. If you are not the intended recipient, do not read, copy, disclose or otherwise use this message. The sender disclaims any liability for such unauthorized use. PLEASE NOTE that all incoming e-mails sent to Weatherford e-mail accounts will be archived and may be scanned by us and/or by external service providers to detect and prevent threats to our systems, investigate illegal or inappropriate behavior, and/or eliminate unsolicited promotional e-mails (spam). This process could result in deletion of a legitimate e-mail before it is read by its intended recipient at our organization. Moreover, based on the scanning results, the full text of e-mails and attachments may be made available to Weatherford security and other personnel for review and appropriate action. If you have any concerns about this process, please contact us at dataprivacy at weatherford.com.