CODEWITHSUNDEEP
nginx
Fanday
Fanday

Reputation: 101

About Nginx status

This is my nginx status below:

Active connections: 6119
server accepts handled requests
 418584709 418584709 455575794 
Reading: 439 Writing: 104 Waiting: 5576

The value of Waiting is much higher than Reading and Writing, is it normal?

Because of the 'keep-alive' is open?

But if I send a large number of requests to the server, the value of Reading and Writing don't increase, so I think there must be a bottleneck of the nginx or any other.

Upvotes: 4

Views: 6353

Answers (2)

Déjà vu
Déjà vu

Reputation: 28850

The Waiting time is Active - (Reading + Writing), i.e. connection still opened waiting for either a new request, or the keepalive expiration.

You could change the keepalive default (which is 75 seconds)

keepalive_timeout 20s;

or tell the browser when it should close the connection by adding an optional second timeout in the header sent to the browser

keepalive_timeout 20s 20s;

but in this nginx page about keepalive you see that some browsers do not care about the header (anyway your site wound't gain much thanks to this optional parameter).

The keepalive is a way to reduce the overhead of creating the connection, as, most of the time, a user will navigate through the site etc... (Plus the multiple requests from a single page, to download css, javascript, images etc...)

It depends on your site, you could reduce the keepalive - but keep in mind that establishing connections is expensive. This is a trade-off you have to refine depending on the site statistics. You could also decrease little by little the timeout (75s -> 50, then a week later 30...) and see how the server behaves.

Upvotes: 2

Randall Hunt
Randall Hunt

Reputation: 12592

You don't really want to fix it, as "waiting" means keep-alive connections. They consume almost no resources (socket + about 2.5M of memory per 10000 connections in nginx).

Are the requests short lived? it's possible they're reading/writing then closing in a short amount of time.

If you're genuinely interested in fixing it you can test to see if nginx is bottleneck you could set keep-alive to 0 in your nginx config:

keepalive_timeout 0;

Upvotes: 0

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