0
votes
1answer
13 views

iptables and TPROXY support

I'm running iptables v1.4.21 on Ubuntu 14.04 and is trying to setup iptables to use TPROXY. How can I check whether my current build of iptables supports TPROXY? I can check TPROXY support for ...
1
vote
0answers
104 views

Haproxy using 10GB Memory and 100% CPU with 50k connections

On a Ubuntu 14.04 x64 server, Haproxy uses 3.3 GB of memory and 6.8 GB of swap, while handling 52k connections. The CPU usage also keeps spiking to 100% before most of the traffic was redirected to ...
0
votes
1answer
29 views

Prevent TCP Connections from Timing out on Restarting Service

On Ubuntu 14.04, an app communicates with clients at intervals of about 1 per sec to 1 per min. However the service have to be restarted regularly and this causes all the connections to drop/timeout. ...
0
votes
1answer
123 views

pushing apache2 past 1500 concurrent connections

I am trying to scale to 4000 concurrent connections on a ubuntu/apache box. It is 8 core / 64gb ram, so it is not hitting memory or cpu, or any resources for that matter. The problem is with ...
0
votes
1answer
91 views

How to view tcp connection errors in apache/ubuntu

I am load testing a ubuntu/apache2 server and after 500 concurrent connections my load testing software is telling me there are connection errors. The errors are not showing up in apache error log. ...
2
votes
1answer
138 views

How to configure tcp wrapper

I have a server with ip-address 192.168.0.1 and a client with ip-address 192.168.0.2 both of them are able to connect with each other. Now the problem is I have configured TCP Wrapper on my server ...
1
vote
2answers
159 views

How can I release a port that is still in use but not bound to a process?

I'm running a Python application that spawns multiple processes. It uses port 56008 to listen for client requests. Sometimes after closing it the port it used is still "in use". There are still some ...
5
votes
1answer
718 views

How to expose a UNIX domain socket directly over TCP

I'd like to have a UNIX domain socket, say /var/program/program.cmd for example, exposed via TCP, lets say on port 12345. I'd also like this to be running full time in the background. What's the best ...
0
votes
0answers
73 views

Cant connect to mysql server

I'm trying to configure a freshly installed mysql server to listen on port 3306. I've removed skip_networking, I have changed bind-address=172.20.33.1 (which is my server ip) and it completely ...
0
votes
2answers
924 views

How do I get my ubuntu server to listen for database connections?

I am having a problems connecting to my database outside of phpmyadmin. Im pretty sure this is because my server isn't listening on port 3306. When I type: sudo netstat -ntlp on my OTHER working ...
1
vote
0answers
509 views

MySQL crashes when connecting from localhost with tcp (UNIX sockets work)

I have Ubuntu 12.04 running MySQL server 5.5.24. I can connect with mysql --user root -p. status shows me : ... Connection: Localhost via UNIX socket ... When I try to connect with mysql --host ...
0
votes
3answers
4k views

Why is UDP slower than TCP on Ubuntu Server?

I transfer data between two Ubuntu Servers (12.04) via iperf on 1Gb LAN. iperf -s <-> iperf -c <addr> -n2G TCP speed = 925 Mbits/sec iperf -su <-> iperf ...
2
votes
1answer
2k views

Why am I seeing dropped packets in the NIC stats on my Ubuntu server?

I see dropped packets using ifconfig on my eth0 interface: eth0 Link encap:Ethernet HWaddr 00:15:17:0d:03:ca inet addr:10.0.1.2 Bcast:10.0.1.255 Mask:255.255.255.0 UP BROADCAST ...
2
votes
2answers
306 views

Apache not processing new requests without reaching max_client value.With many idle children

we are facing a problem,that new requests are not processed even if apache hasn't reached its max_client setting. Max_client is set to 800 max_spare server is 36 min_spare server is 35 ...
1
vote
1answer
373 views

Slow performance over network (Ubuntu)

i did setup this NodeJs TCP Server and tested it with a message flooder. Just to see how the performance of the server is. While the message throughput is great if i run the server and the message ...
3
votes
2answers
4k views

Changing TCP window size on an Ubuntu server

Is there any way to start with a larger than default TCP window size on an ubuntu server? I see there are some parameters in /proc/sys/net/ipv4/ e.g: /proc/sys/net/ipv4/tcp_window_scaling (which is ...
2
votes
2answers
377 views

In Ubuntu, is there something I can run that checks the HTTP requests coming in?

I'm running Node.js. But for some reason, requests are not being caught by the server. (http://stackoverflow.com/questions/9247482/node-js-server-not-receiving-ajax-requests) Is there any way to ...
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 ...
1
vote
3answers
1k views

Linux Server does not respond to TCP connections after some time running. How to analyse?

My Ubuntu 11.04 server on the internet has some strange behavior since a few days. It runs perfectly fine with some Java web applications. Then, suddenly it does not accept connections anymore. When I ...
-3
votes
1answer
546 views

how to open tcp port in ubuntu

I have a ubuntu server How can i open a port ? I have flushed the iptables and off'ed ufw Provide me steps how to open a tcp port
0
votes
2answers
742 views

Server Dropping all Connections Randomly and Packet Loss

I just built a server using a Supermicro X8DAH+-F board and running Ubuntu 10.04 Server 64bit. This has the Intel 82576 dual port controller (one port is disabled). Since this is a server, remote ...
2
votes
2answers
579 views

Ubuntu: Compressed, but not encrypted, tunnel for TCP?

How can I set up a tunnel for TCP connections between two hosts so that I can test a few different compression algorithms? I'm aware of stunnel & SSH, but want to avoid the overhead of ...
0
votes
1answer
206 views

How do I find which process is dropping my TCP ACKs on a dual-homed machine?

I have a dual-homed machine (1 LAN, 1 DMZ) using static IPs on both, with routes configured so that packets coming in on the LAN IP use a LAN gateway and DMZ packets use a DMZ gateway. I am using ...
0
votes
1answer
215 views

Detect and aggregate packets sent to server per TCP port

Is there a way with Ubuntu 10.4LTS to detect and aggregate the number of packets transmitted over every port? In other words, I'd like a process to keep track of the number of packets sent to each ...
4
votes
2answers
2k views

Remote server hangs, gets stuck. How to debug?

I have an vps running on VmWare ESX with Ubuntu 8.04 LTS. It has been running smoothly for the past 3 months, however recently we've notices two strange bugs. a. The server hangs, today was second ...