Consul PUT api does not reuse tcp connection

[hehailong5]

version: from 0.8.4 to the latest

We've tried version 0.8.4, 1.6.6 and the latest, and found /v1/catalog/register and /v1/catalog/deregister have this problem. this could leave a bunch of TIME_WAIT entries and finally exhaust the fds.

[dnephin]

Thank you for reporting this issue! I think this may be the same issue that was reported in #3316. Can you tell us more about how you are making those API calls? Are you using the consul/api client library, or are you using some other http client?

[hehailong5]

Hello,

We use the consul/api client library in our golang program with the client created with api.DefaultConfig()

[boxofrad]

Hi @hehailong5 👋🏻

I've taken a look at this today and was unfortunately unable to reproduce the issue you've encountered. I do have a couple of observations, though:

1. Connections cannot be re-used/shared between HTTP/1.1 requests made in parallel (without pipelining, which isn't well-supported). If you're making requests from multiple goroutines then it may account for this behavior.
2. The default HTTP transport has an IdleConnTimeout of 90 seconds and has a limit on the number of idle connections that will be held open (this is derived from GOMAXPROCS). If your code makes infrequent use of the client, or sleeps for longer than 90 seconds between use, it's likely that connections will have been closed. These settings can be overridden by providing your own http.Transport.

Hope that helps! Please let us know if you're still encountering problems.