From: Paul Henry <paul@wanelo.com>
To: unicorn-public@bogomips.org
Subject: High number of TCP retransmits on Solaris
Date: Tue, 22 Jul 2014 11:52:18 -0700 [thread overview]
Message-ID: <CALKdqYVOyA1fFAVgEb6Z56Y3guSV7U-P_LS0YTmD3Q1BujmKCw@mail.gmail.com> (raw)
Hello!
When using unicorn unicorn v4.8.2, we're seeing a high number of TCP
retransmits at a high connection rate.
Smartos version: 20131218T184706Z
Rackup file used:
> cat server.ru
run -> (env) { [200, {"Content-Type" => "text/plain"},
[Time.now.iso8601(6)]] }
To start unicorn:
> bundle exec unicorn -l 9292 server.ru
To benchmark unicorn:
>> Benchmark.measure { 1000.times { time=Benchmark.measure { open("http://<ip>:9292/api/v1/settings/time",
"Host" => "api.wanelo.com")}.real; p (time*1000).round(2) if time > 0.05 } }
After the total number of connections on the system goes above 8,000
(16,000 is the average number of connections), we start seeing delays of
around 1.1 seconds.
We don't see the issue over the local loopback interface, only over the
net. When using Webrick, we also don't see this issue.
Our tcp initial retransmit interval is 1 second. When the interval is
reduced, the occasional latency goes down. We also see the retransmits in
netstat, about 1 - 2 every second.
Anything that we should look at next?
Thanks!
Paul
next reply other threads:[~2014-07-22 18:52 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-22 18:52 Paul Henry [this message]
2014-07-22 18:57 ` High number of TCP retransmits on Solaris Michael Fischer
2014-07-22 19:03 ` Paul Henry
2014-07-22 20:56 ` Eric Wong
2014-07-22 21:56 ` Paul Henry
2014-07-22 22:07 ` Michael Fischer
2014-07-22 22:10 ` Michael Fischer
-- strict thread matches above, loose matches on Subject: below --
2014-07-22 18:51 Paul Henry
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://yhbt.net/unicorn/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CALKdqYVOyA1fFAVgEb6Z56Y3guSV7U-P_LS0YTmD3Q1BujmKCw@mail.gmail.com \
--to=paul@wanelo.com \
--cc=unicorn-public@bogomips.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://yhbt.net/unicorn.git/
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).