Questions tagged [time-wait]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
0 answers
45 views

How to block flooding "empty" connections from single IP

Right now netstat lists 200 - 4000 connections to the same IP in India. Seems like some kind of flooding attack to me. e.g: tcp 0 0 [removed] 182.65.238.[removed].in-:mysql TIME_WAIT I've ...
  • 1
0 votes
1 answer
102 views

Why does one of four-way handshake miss with the command nc

I'm using the command nc to simulate the TCP connection with a client and a server. I execute the command nc -l 1234 and tcpdump -i eth0 port 1234 at the server and I execute the command nc ...
  • 117
0 votes
0 answers
197 views

How to check on CentOS 7.7 which process take 1 min because of slow page loading (TTFB 1 min)

I'm using CentOS version 7.7. A few days ago my frontend page (not whole website) TTFB is exactly 1 min. How I can check which process causes that? I'm using PHP 7.3 php-fpm ON Any way to check which ...
  • 101
0 votes
0 answers
31 views

Why is server is waiting with second request untill first is fisnished

Not sure what it is, but everytime I try to run one http request from browser, second must wait for first to fisnish. Is it server side configuration/seciurirty? For example, I have 2 files long.php ...
  • 1,181
0 votes
0 answers
219 views

How to configure for many stateless requests?

I am a data scientist / machine learning developer. Sometimes, I have to expose my models by providing an endpoint. I usually do this via Flask and gunicorn: exampleproject.py: import random from ...
3 votes
2 answers
70 views

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 ...
1 vote
1 answer
2k views

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 ...
7 votes
1 answer
4k views

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/...
6 votes
2 answers
11k views

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 ...
  • 471
0 votes
1 answer
131 views

my website can get ping but status always "Waiting" when visiting via browser

When i tried to use CMD.exe and then typed : ping fgroupindonesia.com it returns a true respond such as : C:\Users\admin>ping fgroupindonesia.com Pinging fgroupindonesia.com [219.83.68.83] ...
  • 101
0 votes
1 answer
496 views

Netcat - socket in time_wait when echoing and piping, but not when invoked directly

I'm testing an application using netcat (nc) and I'm getting very low throughput on network connections. When I ran netstat -tnpo I see numerous TCP sessions in TIME_WAIT. I'm sending data to my ...
  • 230
1 vote
0 answers
154 views

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 ...
-4 votes
1 answer
301 views

Why is the same socket in TIME_WAIT many times?

I have read other threads regarding sockets in TIME_WAIT, but I am clearly still missing something. Below is a few lines from a "netstat -an". How could it get into this situation? If I understood ...
3 votes
0 answers
764 views

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 ...
0 votes
1 answer
2k views

How to trace TIME_WAIT sessions using tcpdump (or similar tool)

I have a server with large number of TIME_WAIT sessions. These are sessions that the server closed, but the client didn't close. I want to analyze a sample session, to understand what happens there. ...
4 votes
1 answer
8k views

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 ...
4 votes
1 answer
8k views

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-...
  • 172
1 vote
0 answers
127 views

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 ...
  • 213
6 votes
1 answer
2k views

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 ...
  • 311
1 vote
1 answer
4k views

Lots of TIME_WAIT from same IP address

I've seen a lot of questions with people concerned about lots of TIME_WAITs in netstat. I'm having a similar problem but all the TIME_WAITs are coming from the same IP address. I get over 200 of the ...
0 votes
1 answer
787 views

Limiting outgoing connections by port to control nf_conntrack usage

I would like to make my system more resilient against certain failure. When the system makes rapid outbound TCP connections fail, the nf_conntrack table fills up with TIME_WAIT entries. This ...
  • 520
1 vote
2 answers
2k views

How to diagnose large number of TIME_WAIT connections

We have a production issue with only one of our servers and have correlated slow performance to an abundance of sockets in the TIME_WAIT state. Without drawing this question into a huge backstory, we ...
  • 139
8 votes
1 answer
104k views

Avoid TIME_WAIT connections [duplicate]

When I use netstat command it shows.. tcp 0 0 localhost:18056 localhost:mysql TIME_WAIT tcp 0 0 localhost:16683 localhost:mysql ...
1 vote
1 answer
6k views

How to reduce the timeout for TIME_WAIT connections on OpenBSD?

I'm running http_load on OpenBSD 5.2, to test how good my nginx setup is, and I've noticed that cold runs are much faster than warm runs, and with every run the performance goes down very dramatically ...
  • 13k
0 votes
1 answer
414 views

PHP Adodb many sleeping connections

Already asked the question on stackoverflow but i guess this might be a better place for it. I'm currently struggeling with a strange problem: while using adodb as connection layer for php, it leaves ...
  • 111
0 votes
1 answer
675 views

Debian/Apache Server waiting time very slow only with Chrome

I have a website running on a Linux Debian Squeeze server with Apache 2. The website is the only one on the server and the traffic to the website is very low (800-1000 connection per day). The ...
7 votes
1 answer
6k views

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. ...
  • 367
1 vote
0 answers
560 views

Does TIME_WAIT affect dynamic ports?

I've read a bit about TIME_WAIT connections, and know they should be harmless to my server (connection closed, so no resource connected with this socket). Recently, my server reached the magic ...
  • 61
1 vote
1 answer
881 views

Connection between nginx and Varnish

I am using nginx as reverse proxy with varnish in the background. I have LAMP fueling varnish. The problem I am seeing on Varnish server is that the connection from nginx is getting established ...
  • 1,117
1 vote
0 answers
3k views

Lots of TIME_WAIT connections with nginx reverse-proxy

I'm using nginx as reverse proxy to redirect some traffic to openfire XMPP server. Here's what I see in netstat: 972 connections to port 80 from outside (includes website and redirected XMPP over ...
  • 1,289
4 votes
1 answer
196 views

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 ...
  • 155
5 votes
2 answers
2k views

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 ...
  • 1,211
2 votes
2 answers
936 views

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 ...
  • 229
0 votes
2 answers
1k views

Newly configured MSSQL2008, TIME_WAIT but no ESTABLISHED?

Windows 2008 R2, standard. No firewall locally on it. Newly setup because an old SQL2000 had two disks die (or could it be the raid controller?) at the same time. Luckily, I had fresh backups. The ...
  • 4,340