A connection generally refers to a TCP/IP connection, that is established as the result of the handshake between 2 hosts.
21
votes
4answers
3k views
Why do consoles sometimes hang forever when SSH connection breaks?
I've seen this with so many consoles (on Linux, Mac, ...), and with lots of different machines in many different networks. I can never pinpoint the exact reason, why this happens: All you have to do ...
9
votes
3answers
100 views
Log connections to program
Besides for using iptables to log incoming connections..
Is there a way to log established inbound connections to a service that you don't have the source to (suppose the service doesn't log stuff ...
8
votes
3answers
1k 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 ...
7
votes
6answers
5k views
How to force MySQL to connect by TCP instead of a Unix socket?
I would like to analyze mysql traffic. Right now, all mysql requests are sent to the MySQL unix socket:
unix 2 [ ACC ] STREAM LISTENING 3734388 15304/mysqld ...
7
votes
1answer
3k views
Remote connection to MySQL server takes very long
I have a MySQL 5.0.75 server running on my Linux notebook to which I want to connect from another machine in the local network.
This connection takes 5-6 seconds:
mysql -h 172.22.65.101 -u myuser ...
7
votes
2answers
3k views
Connection error to mysql database
My application needs to do quite frequent connects to a mysql database on another machine. However I get frequent errors on connection; I can usually eventually connect but after many retries. The ...
6
votes
2answers
3k views
Certificates in SQL Server 2008
I need to implement SSL for transmissions between my application and Sql Server 2008.
I am using Windows 7, Sql Server 2008, Sql Server Management Studio, and my application is written in c#.
I was ...
6
votes
1answer
829 views
PHP/mySQL: how to debug a 'too many connections' error?
I am working right now with PHP website on my client's dedicated server and I get periodically an error too many connections but ~5 users are browsing this page.
In phpMyAdmin I can see that max ...
6
votes
1answer
235 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.
...
5
votes
4answers
2k views
mysql connection is slow (5seconds)
After building my webapp on a first boot i create 2 connections to mysql on debian then 1-2 (r/w) for every page after that. The connection consistently take 5.2 seconds to connect. Debian is in a VM ...
5
votes
2answers
107 views
Effects of internet connection speeds on server queries
Can my internet connection significantly effect queries run on phpmyadmin? I am currently 18 down and 30 up. I switched internet connections today and noticed a deep drop in query performance.
The ...
5
votes
1answer
624 views
Should the database connection limit equal the number of processes connecting?
I noticed that PostgreSQL and MySQL have a 100 client connection limit by default. I'm wondering if I should turn this down since the webserver is on the same box and I only have about 20 PHP ...
5
votes
1answer
8k views
Understanding this error: apr_socket_recv: Connection reset by peer (104)
So, if I do some benchmarking with apache benchmark (ab), and I use large numbers of requests. Then sometimes in the middle of a test I get this error.
I don't even know what it means. So how can I ...
5
votes
1answer
183 views
Connecting to AS/400 hardware
In about 2-3 weeks I'm getting an old AS/400 server (something 9406, probably 6xx or 8xx) to learn OS/400 from administrators point of view.
Will I need some special hardware to connect and do IPL ...
4
votes
6answers
400 views
Effect of distance from server on page load speed
I measured the load speed of a static image file severed by nginx from my server (using pingdom service). The server should normally process this request within few seconds. My server is located in ...
4
votes
8answers
1k views
What's better than wifi to connect servers wirelessly (ethernet-like latency)?
I need to connect some servers wirelessly and would like to know what other technologies (than Wifi) exist to get an idea of the possibilities.
It would nice to know the pros/cons, limitations.
...
4
votes
2answers
270 views
Linux box takes 10 seconds to make a connection
My machine is taking 10 seconds to establish a connection. Once the connection is established, it is up to speed and works correctly. But if I for example ping www.google.com, it takes 5 seconds for
...
4
votes
6answers
580 views
What causes a delay of 100 ms in initiating an HTTP connection?
Settings: this is a quad CPU machine, plenty strong, not loaded at all (neither CPU nor network), the client is a Windows Server 2008 64bit, the server is a linux box.
I have four threads that are ...
4
votes
4answers
422 views
How to wire 20 computers and 20 phones and 1 server into LAN?
I have currently 3 switches
Two Netgear JFS524 with 24 slots,
One Belkin with 16 slots.
Server
DSL Internet Router.
Main question is how to connect switches together, two Netgear's are next to each ...
4
votes
2answers
771 views
Impact of Connection Close vs Keep-alive
I'm configuring our servers, and due to the nature of our load balancer, we can't send connection keep-alive headers. I'm trying to determine the impact of sending these headers to both the end-user ...
4
votes
1answer
1k views
Unable to connect to a remote database
I'm playing with MongoDB. I have a good deal of experience with MySQL and was using something called Sequel Pro to connect to remote databases. I'm now trying MongoHub but can't seem to get it to ...
4
votes
2answers
13k views
What is the typical maximum number of database connections for Oracle running on Windows server?
We are maintaining a database server that serve a large number of clients. Each client typically running serveral client-applications. The total number of connections to the database server (Oracle ...
4
votes
1answer
954 views
Load balancing MySQL using HAProxy: Got an error reading communication packets?
I've set up load balancing MySQL slaves using HAProxy via a xinetd. 2 load balancers shared a virtual IP that is managed by Pacemaker:
crm configure show:
node SVR120-27148.localdomain
node ...
4
votes
1answer
836 views
connection sync suggestions with HAproxy and keepalived
I managed to get HAproxy working in a failover configuration as suggested on the architecture.txt document using keepalived.
I used CentOS 5.5, HAproxy rpm (haproxy-1.3.25-1.el5) from epel repo, and ...
4
votes
2answers
194 views
What permission is needed for my SQL Server 2005 DB for a WebUser?
I have a connection string in my asp.net code that looks at a SQL Server 2005 database. I created a UserName called WebUser and granted him db_datawriter and db_datareader in SQL Server 2005. Both ...
3
votes
3answers
6k views
Network packet size on sql server connection string to improve throughput
We have a dataload job that moves a relatively large amount of data across the network between two sql servers. the servers are on the same subnet and there is only a switch between them. the data ...
3
votes
2answers
171 views
How common are encrypted connections between email servers?
alice@a.com --> smtp.a.com --?--> Internet --?--> pop.b.com --> bob@b.com
On the route from sender to server, and server to receiver, encrypted connections (STARTTLS, etc) seem to get ...
3
votes
2answers
1k views
Too many active IP Connections
I have a Linksys WRT54GS v7 with a dd-wrt (micro) installed on.
When I try to view Active IP Connections, I see too many connection there.
Interestingly, there are about 120 connections that originate ...
3
votes
3answers
252 views
Dual external internet connections
We have here 2 Internet connections coming in. And the intention is to have all services available on our server which should be available externally, to be available through both connections.
Also, ...
3
votes
2answers
308 views
Tracking down “Connection reset” errors in Linux
I'm handling large numbers of concurrent downloads (approx. 500 per server) using Java.
All the files are being downloaded from Amazon S3, and the downloading server is an EC2 m1.large instance.
...
3
votes
1answer
39 views
What is a good way to determine a server's connection usage?
Trying to figure out where my system's connections are being used (i.e. how many connections belong to what processes - could even be filtered by some expression through grep, if it applies). The ...
3
votes
1answer
461 views
IPtables rate-limit, What are the differences between modules? Recent, Limit
I am doing some rate-limiting with IPtables, and i'm not sure if I should use "Recent" or "Limit"
What are the differences between the two? If they both achieve the same result, which one has ...
3
votes
1answer
386 views
Windows server closes TCP connection immediately after sending SYN+ACK
After a proper SYN, SYN+ACK and ACK TCP-Handshake, the server immediately sends a FIN+ACK indicating a graceful connection closure. The client's HTTP requests results in RST packets from server. This ...
3
votes
1answer
520 views
Unclosed TCP connections in CLOSE_WAIT for various processes
I have cluster of several machines connected on 10GBE network (NICs are Intel 82599EB 10GBE SFI/SFP+) running under Debian 6.0 and faced with problem of hung up TCP connections in CLOSE_WAIT state. I ...
3
votes
1answer
2k views
Failed to connect to MySQL at localhost
I recently installed MySQL on my machine using MySQL installer. I am using it as part of an Apache Tomcat server I'm running on localhost.
I linked the database to Netbeans and everything was ...
3
votes
2answers
472 views
Intermittent MySQL connection errors
I have been recently getting these errors on my server:
mysql_connect() [function.mysql-connect ]:
Can't connect to MySQL server on 'xxx.xxx.xxx.xxx' (4)
I don't think this is a credentials ...
3
votes
2answers
1k views
How to adjust MySQL performance
I'm facing a real problem with MySQL instance for a service online.
We use hibernate and c3p0 pool with these settings:
c3p0.max_size=200
c3p0.min_size=5
c3p0.timeout=60000
c3p0.max_statements=20
...
3
votes
2answers
486 views
Why does my server lose SQL connection every 2-3 days (reboot fixes)?
Every 2-3 days, my Windows Server 2003 R2 Enterprise box which is hosting a .NET web app will start having an issue. The .NET app stops being able to connect to the SQL server with this error:
An ...
3
votes
1answer
3k views
Can't connect to MySql server on remote server
Connecting to: CentOS v?? with MySql 4.?? in Nashville (example public ip=11.11.11.11)
Stack: Cable modem as gateway > router with forwarding > CentOs Box
Connecting from: Windows 2003 R2 in ...
3
votes
2answers
758 views
How to connect to SQL Server via SQL Server Management Studio 2008?
I can't seem to get this to work. I have an IP address for a SQL Server. I have a login and password.
How can I connect to it and work with it?
3
votes
1answer
827 views
Debugging Connection Issues Between Two Linux Servers
I have two CentOS 5 servers running iptables and apf.
I am having issues connecting with ssh from server 1 to server 2.
I can connect from server 1 to a third server and from that third server to ...
3
votes
6answers
4k views
SQL Server 08 Express error when connecting to localhost - “Timeout expired”. Works with ::1 or 127.0.0.1
EDIT
New info: Navigating to localhost:1434 in Chrome gives me an "ERR_EMPTY_RESPONSE", while other ports give me an "Oops! This link appears to be broken". So it seems to binding ok there?
So ...
2
votes
3answers
679 views
How to configure 2 NICs with 2 different gateways?
I have a server with 3 NICs running RHEL6.
eth0 is connected to the intranet.
eth1 is connected to the Operations and Maintenance Network
eth2 is connected to an automated backup network (doesnt ...
2
votes
2answers
111 views
SSH dies when a lot of text transfers through it
I've got a strange problem with SSH. When I try to do something that sends a lot of text over it, often it will break the connection ("connection reset by peer"). It's not every time, but often enough ...
2
votes
7answers
434 views
Network equipment console cables
A lot of network devices has a terminal RJ-45 socket, which is usually a simple COM-port. So, to configure such a device, you have to connect RJ-45 socket to PC's (or terminal's) DB-9 COM-port. ...
2
votes
1answer
157 views
Wireless Access Point connection benefits over Wireless Routers
While I was doing research on wireless connection limits, I stumbled upon this question. Zypher's answer seems to suggest connection capacity benefits of wireless access points over wireless routers. ...
2
votes
2answers
239 views
SSH Connection Lost
I have recently started using iptables, and I executed iptables -F without knowledge of what it might do. And suddenly I have lost connection to the node. I can't even ping the node. Any help would be ...
2
votes
2answers
1k views
How does apache creates a thread?
While I was talking with my co-workers few days ago, one of them mentioned that apache creates a thread per connection.
What does he mean by per connection exactly?
Let's say I have a HTML file that ...
2
votes
5answers
6k views
SQL - an error occurred during the pre-login handshake
Until yesterday evening, I was able to connect to my server from my local machine. Now, I get the following error:
A connection was successfully established with the server, but then an error ...
2
votes
3answers
273 views
Fast, reliable data transfers from/to China
We are a small company and we will need to transfer rather large amounts of data (10GB+ each time) between Europe and China in the near future.
As many may have experienced, Internet connections to ...
