Web monitoring concepts

[eran]

I've been playing with the web monitoring capabilities of version 1.3.4 and I must say I find them counter intuitive. I may be missing something but the only way I was able to get web monitoring to work was by associating scenarios with specific servers and using "hard coded" URLs. By specific servers I mean that associating a scenario with a template causes the test status to always remain "in progress". It also doesn't work on windows agents.

I'm used to thinking of web monitoring in a server farm context, where there are many identical servers running the same application and each of them has to be monitored separately. In this environment it is better to run the web tests from a different machine, not from an agent installed on the web servers themselves. Zabbix allows that by associating a scenario with a different agent, however the configuration then becomes a disaster because every scenario has to be created multiple times, once for each monitored server.

I see two alternatives to implementing this:

1. If each web monitoring scenario had a list of "targets" the scenario should be executed against. Then when the scenario is run it would be executed multiple times, once against each target in the list.
   In this case the generated items, must be associated with the target hosts, and not as it is now, with the host running the tests.
   In this case the scenario steps should look something like this http://{HOSTNAME}/app/index.htm
   
2. Decide that web monitoring is only executed from the Zabbix server, not from agents. In this case when a scenario is associated with a host, it wouldn't run on that host's agent, but instead would run on the server and would send the HTTP requests to the configured host. This would easily apply to templates as well. So when a scenario is associated with a template it would be executed from the server against all the hosts using that template.
   This alternative limits the locations from which the tests can be run but it may be simpler to implement than the first one

I'll be happy to know if other people need to test whole web farms and if anyone found a way to accomplish that using the web monitoring capabilities of the beta version.

Eran

[Alexei]

Thanks for your comment.

ZABBIX server does not require any agent running o a target host for WEB monitoring. ZABBIX server does everything!

Every WEB scenario is associated with a host application, for example, Sugar CRM. So if you go to WEB screen you will see selection of hosts on the top and list of the host's application below:

Host: www.zabbix.com

- ZABBIX Forums
- ZABBIX Wiki
- Whatever...

Note that you may see application in the "Latest data" screen as well. This is required to get direct access to data collected by each individual scenario and their steps.

Items related to a scenario can be used for normal purposes: graphs, plain text data, screens, triggers, anything. You may alert a web adminitrator in case of one of steps failed, response time is too high, anything. They act as a normal items.

It is not possible to create templates of WEB scenarious at the moment, however you may use the Clone button to simplify creation of similar scenarios.

Please let me know what you think.

[eran]

Hello Alexei,
Thanks for the explanation.

If I understand you correctly the tests are actually run from the zabbix server and the association with the host is only used for allowing the generated items to be associated with that host. Am I correct in my understanding?

About your suggestion to use clone to replicate the scenarios, I'm afraid it's not very useful for two reasons:

1. The clone operation does allow the cloned scenario to be associated with a different host. This can be easily solved if you created a "Copy to" operation, like the one for items.
2. The steps in the scenario use full URLs, with host names, so even if they were cloned, they would still require manual editing of the host names in each steps. This can be solved by supporting macros in the URLs, so {HOSTNAME} could be used, or by allowing relative URLs so the step URL would begin with / and the host name will be implied to refer to the associated host.

Almost last thing, if templates are not supported as legitimate hosts, they should be filtered out of the selection box, that would save a lot of time and trouble.

and a really last thing, the more I play with it the more I realize how powerful this system is - it's really a great tool.

Eran

[Alexei]

If I understand you correctly the tests are actually run from the zabbix server and the association with the host is only used for allowing the generated items to be associated with that host. Am I correct in my understanding?

Absolutely!

About your suggestion to use clone to replicate the scenarios, I'm afraid it's not very useful for two reasons:

1. The clone operation does allow the cloned scenario to be associated with a different host. This can be easily solved if you created a "Copy to" operation, like the one for items.
2. The steps in the scenario use full URLs, with host names, so even if they were cloned, they would still require manual editing of the host names in each steps. This can be solved by supporting macros in the URLs, so {HOSTNAME} could be used, or by allowing relative URLs so the step URL would begin with / and the host name will be implied to refer to the associated host.

I agree. Current solution is not very suitable for monitoring of a number of similar WEB applications. The {HOSTNAME} macro can be easily implemented, yet the most important issue, replication of scenarios, requires more work.

Almost last thing, if templates are not supported as legitimate hosts, they should be filtered out of the selection box, that would save a lot of time and trouble.

They shouldn't! There is nothing special about these hosts. WEB monitoring items must be filtered out (they already are), not hosts.

and a really last thing, the more I play with it the more I realize how powerful this system is - it's really a great tool.

Thanks!

[eran]

The {HOSTNAME} macro can be easily implemented, yet the most important issue, replication of scenarios, requires more work.

If the {HOSTNAME} macro was implemented then replication would not be necessary. It would be possible to create a single test with the macro, and assign it to a template. Then all the hosts that use that template will "inherit" that test and replace the {HOSTNAME} macro with their own name.
Isn't that the way it works?

[Alexei]

It is supposed to work this way. Note that support of well known macros will not be available in 1.4, we plan to introduce it later in 1.4.1.

[Piavlo]

Hi Alexey,

From my testing with zabbix1.8.2 the {HOSTNAME} macro is still not available in web secnarios.
As well if I create a web scenario in template, then it is still NOT activated for any of the hosts which inherit this template.
Also then I use clone it associates the clone with same host - I can't find how to clone from one host to another.

Is there any plans to solve these issues?
I've just started playing with web monitoring and immediately found these
issues to be a major problem.

Thanks
Alex

[jurgenhaas]

I'm in the very same situation and wonder why this is taking so long to implement. Reading through several threads here on the forum highlights that people got indication for an implementation in 1.4, it got dealyed to 1.4.1, then there is a post that says it won't get into 1.6 and that it will be done in 1.8

Now we are on 1.8.2 and it still doesn't seem to be there.

To be fair, I've just joined the party, as you can easily see from the number of posts. So I'm not in a position to be upset but I wonder what's required to accelerate the process. Isn't Zabbix OpenSource so that the community could jump in and get this done?

[Piavlo]

I've opened two tickets on the matter in the issue tracker
ZBX-2479
ZBX-2478

jurgenhaas - I guess what you could do to influence is to vote for these tickets
to be solved in the issue tracker.