This Agent can monitor different parameters from an Apache server. It has been tested in:Apache/2.3.5 (Unix) mod_ssl/2.3.5 OpenSSL/0.9.7d mod_fcgid/2.3.2-dev, Apache/2.2.8 (Ubuntu) and Apache/1.3.31 (Unix) mod_perl/1.24. However, we strongly recommend to test it in a production environment before implanting it.

Apache agent has been developed using the functionalities and improvements of the Osmius framework and ACE libraries. Thus, it is mandatory to install ACE libraries to use this agent. In case of doubt, read the chapter: installation.

Apache agent provides eleven basic events with configuration parameters to allow scalability in an easy way. Events has been selected by the Osmius's R&D team as the most interesting for the first development.

All events are remote and Apache server-status based. Agent checks the information returned by the Apache server through server-status page and then builds a response. Check if your Apache has server-status.
To learn how to activate server-status go to: Apache agent prerequisites

Each Osmius agent usually can monitor one type of instance. If you are unaware of the concepts please go to the glossary. Each instance is defined individually in the configuration file (if you want more information please go to agents and instances). Depending on each agent we have to define the instance type and its connection info.

connection_info or connection information is the information that the agent needs to be able to connect to the instance (more information in connection_info).

In the Osmius's Apache agent case the connection_info prototype would be:

CONNECTION_INFO= -u URL_SEVER-STATUS [-p PORT]

Where we will replace in each declared instance:

• URL_SEVER-STATUS: complete URL to the Apache server-status to be monitored.
• PORT: port number where Apache is dispatching webs.

An example could be:

CONECTION_INFO = -u http://localhost/server-status -p 8080
CONECTION_INFO = -u http://80.53.24.123/server-status

Type defines the type of instance to be monitored. All instances declared must have an associated type as you can see here

In Apache case:

TYPE= APACHE01

Info events recover generic information that don't change very often from the instance. This type of events doesn't have severity, they just offer details about the instance.

AVAILABL checks if Apache server is responding requests. It returns Apache version and associated text as well.

Returned values:

Recommended parameters:

Configuration example:

AVAILABL = -t 60 -c 1 -w 0 -a 0 -T "Apache Intranet"

Remarks: Apache server version is showed in the text associated to the event. For example: Apache/2.2.8 (Ubuntu).

APPARSER returns the number of Parent Servers generated by Apache.

Returned values:

Recommended parameters:

Configuration example:

APPARSER = -t 120 -c 0 -w 25 -a 60 -T "example.com server generation"

Remarks: None.

APUPTIME returns the time that Apache has been working since its last restart.

Return values:

Recommended parameters:

Configuration example:

APUPTIME = -t 300 -c 1 -w 250 -a 100 -T "example.com uptime"

Remarks: Time will be returned in the event's associated text: [X] days [Y] hours [Z] minutes [W] seconds.

APTOTACC returns the number of global access to Apache.

Return values:

Recommended parameters:

Configuration example:

APTOTACC = -t 300 -c 0 -w 1000 -a 10000 -T "example.com total access"

Remarks: None.

APTRAFFI returns the average Apache traffic.

Return values:

Recommended parameters:

Configuration example:

APTRAFFI = -t 3600 -c 0 -w 512 -a 1024 -T "example.com traffic in MB"

Remarks: Event's associated text shows a conversion of the traffic to a more reasonable measure if it's needed: kB, GB …
For example: Total traffic in MB[2048] 2.0 GB

APPRCCPU returns the percentage of CPU consumed by Apache.

Returned values:

Recommended parameters:

Configuration example:

APPRCCPU = -t 600 -c 0 -w 70 -a 85 -T "example.com Apache CPU Usage percentage"

Remarks: None.

APREQMIN returns the average requests per minute received by Apache.

Returned values:

Recommended parameters:

Configuration example:

APREQMIN = -t 900 -c 0 -w 5 -a 10 -T "requests per minute in ApacheCPD3"

Remarks: Average requests per seconds is returned in the event's associated text

APKBSSEC returns the average kbytes sent.

Returned values:

Recommended parameters:

Configuration example:

APKBSSEC = -t 900 -c 0 -w 150 -a 250 -T "KB/s Apache154"

Remarks: None.

APKBSREQ returns the average KBs per request.

Returned values:

Recommended parameters:

Configuration example:

APKBSREQ = -t 900 -c 0 -w 100 -a 256 -T "KBs per request in WebInterna"

Remarks: None.

APCURREQ returns the number of current requests.

Returned values:

Recommended parameters:

Configuration example:

APCURREQ = -t 120 -c 0 -w 10 -a 20 -T "Current requests in Apache"  

Remarks: None.

APIDLWRK returns the number of inactive workers o servers in Apache.

Returned values:

Recommended parameters:

Configuration example:

  APIDLWRK = -t 900 -c 1 -w 25 -a 10 -T "Inactive servers"

Remarks: None.

To be able to compile this agent we need some prerequisites that are generic for the compilation of any Osmius agent, you may know more about them in: prerequisites.

Specifically, for the Osmius's Apache agent we need to install mod_status or mod_info, depending on the Apache version. We do this in order to activate the web page “server-status” generated by Apache.

For the Apache version 1.3 we must install mod_status and for Apache 2.x mod_info. Go to this web to get more information about Apache modules: http://modules.apache.org/

To conclude we have to activate the Apache directive ExtendedStatus, to do this we must add the next sentence in the Apache config file:

ExtendedStatus On

Make sure that you can reach the server-status page from the Apache agent location. In our case, we had to edit status.conf file (/etc/apache2/mods_enabled) and add a command named Allow from followed by the agent host IP.

• Osmius uses Make Project Creator (MPC) to make easier the creation of Makefiles. If you want to know more about MPC in Osmius visit Makefiles in Osmius.

• In the specific case of the Apache agent we can easily create the Makefile this way:

From the agent folder using the console or terminal.

Linux:

$ACE_ROOT/bin/mpc.pl -type make osm_ag_apache.mpc

HP-UX:

$ACE_ROOT/bin/mpc.pl -type gnuace osm_ag_apache.mpc

Windows with Visual C 8:

%ACE_ROOT\bin\mpc.pl -type vc8 osm_ag_apache.mpc

• Now that we have the Makefile, compiling the agent is very easy.

Linux:

make -f Makefile.Osm_Ag_Apache_Osmius

HP-UX:

gmake -f Makefile.Osm_Ag_Apache_Osmius

Windows:

Double click over Osm_Ag_Apache_Osmius.vcproj and the project will be opened in Visual Studio. In the configuration of the solution select Release. Press Rebuild to compile.

Binaries will be automatically installed in the bin folder of the OSM_ROOT base

Apache agent shares the same execution caracteristics with the rest of the agents. You can learn more in Starting and stopping agents.

To execute Apache agent:

Osmius's Apache agent, as the others Osmius agents, allows the execution in standalone mode. This option can be useful when we are developing a new agent or to perform concept tests of an agent.

You only must add a new value in the configuration file of the Apache agent (osm_ag_APACHE01.ini) named SNDCMD as you can see here.

Then you have to execute the Apache agent setting the communications port with the Master Agent to zero. For example:

Tests made to Osmius's Apache agent.