0
votes
0answers
19 views

Single TCP-CLOSE_WAIT connection brings down application till restart

Recently found a behaviour where my application had a connection in TCP Close_wait state till the app was restarted (after about 5 hours). But during this period the SUnreclaim space was also ...
-1
votes
0answers
22 views

High data on recv-q buffer and thread lock on java.io.BufferedInputStream in linux

We have a java application running on linux (ubuntu server). We have been facing high recv-q problem since quite some time. Application gets hang and does not read data from socket every few hours. ...
2
votes
1answer
888 views

Tuning tcp_keepalive_time for Node.js leak

I'm currently having a socket leak with my Node.js application. This bug is also posted here. I hope to fix this soon. CLOSE_WAIT and FIN_WAIT2 seem to be the major problem. Connections: 1662 ...
0
votes
2answers
155 views

Simulating many client connection to server

I've written a protocol on top of TCP using C# Sockets class which allows the transfer of files between many clients, and put it on a Windows Server 2008 VPS. I have then written the client-side ...
2
votes
0answers
109 views

what can put linux process managing connection pool into bad state, so it restarts them continously?

I have an application with pool of connections to MySQL. At some point, in production, every 1-3 seconds some socket is closed. As a result my app restarts this connection. This is pretty big pool ...
3
votes
1answer
624 views

Where are my TIME_WAITs on Mac OS X?

No TIME_WAITs on Mac OS X Normally, when a TCP connection is closed, the socket on the side where close() is called first is left in the TIME_WAIT state. When one of the peers is a Mac OS X (Lion) ...
1
vote
1answer
362 views

Redhat linux: Slow start of new socket connections

I am having problems with a Red Hat server 2.6.18. The creation of a new TCP socket takes very long - once it is established it is fine. iptables and selinux are disabled - is there any other ...
1
vote
1answer
387 views

WSAENOBUFS errors when performing HTTP connections on Windows Server 2008 x64

We are trying to transfer large number of files from a network share into Openstack using a custom written Erlang application (using Erlang version R15B). After about 20k files transferred the Erlang ...
0
votes
1answer
132 views

Socket(TCPIP) Unstable

I have a setup of a SCPI server in a Win7 PC and have 2 other programs talking to it locally(127.0.0.1) over TCPIP socket 5025 and 5029. This worked well and stable in a fresh PC, but when we moved ...
1
vote
0answers
550 views

Disable kernel processing of TCP packets for raw socket

I'm working on a TCP/IP implementation, for an embedded device, that I want to test from a Linux user space process using raw sockets. raw(7) says that Raw sockets may tap all IP protocols in ...
3
votes
2answers
5k views

Exhausting Linux machine TCP socket limit (~70k)?

I am the founder of torservers.net, a non-profit that runs Tor exit nodes. We have a number of machines on Gbit connectivity and multiple IPs, and we seem to be hitting a limit of open TCP sockets ...
4
votes
2answers
5k views

What are the ramifications of setting tcp_tw_recycle/reuse to 1?

I set both tcp_tw_recycle/reuse to 1 in my configuration file. What are the ramifications of doing this? If a tcp socket is re-used, does that pose a security risk? i.e. 2 different connections both ...
6
votes
5answers
3k views

Does the TCP source port have to be unique per host?

I've learned that a TCP connection is identified by the tuple (source IP, source port, destination ip, destination port). Theoretically, it should thus be possible to have a client from host1:port1 ...
2
votes
1answer
87 views

Host information with TCP port

Forgive this question, I'm a designer trying to get my head around a possible network architecture. I have a wildcard domain on example.com. The client connects via TCP to foo.example.com:1234. Is it ...
1
vote
2answers
615 views

Poor TCP loopback throughput on Windows

I measured the throughput of a locally bound TCP socket connection on my computer (Intel Q9550, 64 GB RAM, Windows XP 64 bit) using iperf. I got dissatisfying results (around 1.6 Gbit/s) each time, no ...
11
votes
3answers
8k views

Sockets found by lsof but not by netstat

I have an application which is running out of file descriptors, apparently by opening sockets, but I can't find out exactly what these sockets do. These appear in the lsof output as java 9689 ...
8
votes
3answers
2k views

Can I make TCP/IP session to run less than 60 seconds?

Our server is overloaded with TCP/IP sessions, we have 1200 - 1500 of them. Most of them are hanging in TIME_OUT state. It turns out that a connection in TIME_OUT state occupies a socket until 60 ...
0
votes
5answers
2k views

Lingering tcp connection in LISTEN state

My java application can sometimes be killed by an external script. This can be done either with SIGTERM or with SIGKILL. The application is a server which receives many connections per second, and it ...
0
votes
3answers
347 views

Aggregated throughput of multiple connections (Linux)

Why do multiple connections from the same host achieve better throughput than multiple connections from different hosts? I suspect is something kernel-related (Linux) but a confirmation would help a ...
57
votes
7answers
69k views

How to forcibly close a socket in TIME_WAIT?

I run a particular program on linux which sometimes crashes. If you open it quickly after that, it listens on socket 49201 instead of 49200 as it did the first time. netstat reveals that 49200 is in ...