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Questions tagged [time-wait]

34 questions
8
votes
1 answer

Avoid TIME_WAIT connections

When I use netstat command it shows.. tcp 0 0 localhost:18056 localhost:mysql TIME_WAIT tcp 0 0 localhost:16683 localhost:mysql TIME_WAIT tcp 0 0 localhost:16701 …
Himanshu Matta
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7
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1 answer

why linux reuse 'time_wait' port?

As I know, tcp port in 'time_wait' stat cann't be used. However, in my experiment, server reuses the 'time_wait' port? Why? Firstly, in client machine, type command ehco 40000 40001 > /proc/sys/net/ipv4/ip_local_port_range. So, the maximum number of…
Pengcheng
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7
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1 answer

https lingering TIME_WAIT connections

From my client PC I'm connecting to a webserver, it uses HTTPS only. When I connect I see in TCPView (sysinternals tool alternative to netstat) a lot of TIME_WAIT connections to the https endpoint. Lots of the time I see 11 connections lingering for…
Jaap
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6
votes
2 answers

Why isn't net.ipv4.tcp_rfc1337 enabled by default?

The tcp_rfc1337 setting seems to have a solution for TIME-WAIT Assassination. The first problem is that old duplicate data may be accepted erroneously in new connections, leading to the sent data becoming corrupt. The second problem is that…
Nuno
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6
votes
1 answer

Redis connection issue

We are currently experiencing a lot of Redis errors with the message Unable to connect: read error on connection, trying next server We run Redis on FreeBSD using PHP Redis and we have a hard time reproducing the error on Ubuntu so this might be a…
mre
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5
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2 answers

Network error with 65k of TIME_WAIT connections

We had some trouble with one of our image servers last week and need some help. See our munin monitoring graph: We are runing debian squeeze and we have lots of requests because this is one of our image servers. We do not use keep-alive (maybe we…
Janning
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4
votes
1 answer

High # of sockets in TIME-WAIT state, server unresponsive at load

Our app became unresponsive at high loads, with longer wait times. Process usage was abnormally low (~15% CPU utilisation per process, our app runs on 8 processes). Nginx error log output showed a number of these: 2014/12/04 03:39:31 [crit] 24383#0:…
Julian H. Lam
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4
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1 answer

Relationship between tcp state TIME_WAIT & HTTP keep-alive

What is the relationship between keep-alive on a HTTP request and a tcp socket in TIME_WAIT - should they be correlated? Furthermore, should system and web server settings be aligned e.g. server.max-keep-alive-idle = 60? According to How to reduce…
aland
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4
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1 answer

Can a TIME_WAIT connection be restored?

Is it possible to restore a connection that is in state TIME_WAIT? If not, I use raw packets (forgering the source), is it possible? (Please understand that I do not intend to do bad things, it's just a matter of curiosity)
jyz
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3
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2 answers

How to project / measure physical host wait with multi-core guests in ESXi

I’ve heard that if you have a guest with N virtual cores under ESXi, the hypervisor waits for N total logical processors on the host to become available simultaneously before delegating work from the guest to the hardware. Therefore, the advice is…
Chris Tonkinson
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3
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0 answers

Why is SQL Server using all ephemeral ports connecting to itself and causing TIME_WAITs?

I've got an AWS server with Windows 2008 R2, SQL Server 2012, and Tomcat 7. When I run netstat -ano the screen is flooded with TIME_WAIT. I posted the output in a Gist. When I run CurrPorts, filter on port 1433, and turn on Auto Refresh, I can see…
jordanbtucker
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2
votes
2 answers

TIME_WAIT Info (reduce)

I have a ajax application that makes a request every 3 seconds, the requested page sets the header to (header("Connection: Keep-Alive, close");) then performs a database query and returns the latest data. The value for TIME_WAIT is 60 seconds, so…
Akash
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1
vote
1 answer

Overwhelmed by "TCP: time wait bucket table overflow" errors -- What can I do to mitigate?

I've got a legacy system running Debian 7 (proxmox) hosting OpenVZ containers, and I'm seeing a troublesome problem where the system is being overwhelmed by open connections to VZ container running the apache frontend. When this is happening, the…
Ross Messiah
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1
vote
0 answers

Why might a connection stay in TIME_WAIT for hours or even days?

Our environment is ubuntu 12.04 on EC2. I know TIME_WAIT is a good thing, and I know generally it's OK to see connections remain in TIME_WAIT for up to 2 minutes according to all the reading I've been doing. However, we have instances which have…
Joshua Buss
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1
vote
0 answers

periodic connection timeouts to nginx server

We have the following setup: One nginx server as a loadbalancer in front of four worker application servers. The nginx server get about 100 requests per second, sometimes more that that, active connection are hovering at 110 in average. In a…
Malax
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