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Emma is a graphical toolkit for MySQL database developers and administrators. It provides dialogs to create or modify MySQL databases, tables, and associated indexes. The results of an executed query are displayed in a resultset where the record data can be edited by the user, if the SQL statemant allows for it. The SQL editor and resultset view are grouped in tabs. Results can be exported to CSV files. Multiple simultaneous opened MySQL connections are possible. Emma is the successor of yamysqlfront.

I was recently stumped by an odd incoming network connection hang problem on a linux server. This is a writeup of how I troubleshot the issue and eventually fixed it.

Sendmail does not provide a command-line argument to remove messages from the mail queue. It may be necessary to manually remove messages from the mail queue rather than allowing Sendmail to attempt redelivery of messages for Timeout.queureturn days (5, by default).

The proper way to remove messages from the mail queue is to use the qtool.pl program included in the contrib subdirectory of the Sendmail source code distribution. qtool.pl uses the same file locking mechanism as Sendmail...

Adjusting sendmail queue time / lifetime

By default, sendmail will keep items in the queue for up to 5 days. If you want to make this something shorter, like 3 days, you can adjust the following in /etc/mail/sendmail.mc:

If you want to change speed and duplex of your network card you have to use ethtool or mii-tool.ethtool can be used to query and change settings such as speed, auto- negotiation and checksum offload on many network devices, especially Ethernet devices.

So you think your OpenVZ VPS really has “guaranteed memory”? Well. Not quite. I have got an OpenVZ VPS from one of the providers listed here — 256MB guaranteed and 512MB burstable memory. When I run free it shows... 512MB total memory and 0 swap? After all I am only using 65MB of memory so well below my “guaranteed” amount. Zero swap because it is just how OpenVZ does its memory account. But is it really the case that all my processes reside in physical RAM?

Let’s dig out the good ol’ user_beancounters...

Experimenting with Varnish...
Using the varnish HTTP accelerator - Experiences so far...

The best way to think of things is that as a request comes in, Nginx will scan through the configuration to find a “location” line that matches the request. There are TWO modes that nginx uses to scan through the configuration file: literal string matching and regular expression checks. Nginx first scans through ALL literal string location entries in the order that they occur in the configuration file, and secondly scans through ALL the regular expression location entries in the order that they occur in the configuration file. So be aware – location ordering order DOES matter...

Nginx is a fast and efficient web server. It can be configured to serve out files or be a reverse proxy depending on your application. What makes this web server different from Apache, Lighttpd or thttpd is the overall efficiency of the daemon, the number of configuration options and how easy it is to setup....

Synaptic is a graphical user interface (GUI) for managing software packages on Debian-based distributions. If you are using Debian or Ubuntu you will easily find Synaptic in the System Tools menu or in the Administration menu.This tutorial will explain how to install,remove and upgrade packages using Synaptic in ubuntu.