Polling Frequency And Alert Precedence

[rockeis]

Hi,

I installed MonYog at a customer site while trying to resolve a customer problem. We're getting some perhaps strange results and looking for help in understanding how MonYog works.

At the customer site we have a Tomcat based application running on a customer's web server. It connects to a MySQL 4.1 database over a network. Tomcat is occasionally freezing and it is appearing that connecting to the database is a symptom, if not the problem.

To help diagnose the problem, I installed MonYog on another computer and set it up for email alerts. On the webserver computer, I installed a simple Java based program that opens a connection to the database, does a select 1 query and closes the connection at 20 second intervals.

Over the weekend, the following happened. Over a roughly 7 minute period MonYog sent emails related to % of refused connections. The monitoring program I wrote over the same period had no problems. During that period Tomcat ran into problems, froze, and had to be rebooted.

Questions

1. At what frequency does MonYog generate emails by default? How is it set and is it adjustable?

2. If more than 1 monitored parameter is over threshold when MonYog is about to send an email, does it send them all or does it prioritize? If it does prioritize, how does it do so?

3. Any ideas why the Java program was able to connect over the same time period that MonYog wasn't? Some sort of network disruption between the MonYog computer and the database computer seems to be the obvious scenario.

Thanks

[Sayan Chaliha]

Hi Rockeis,

Here are answers to your questions:

1. This would depend on which version of MONyog you are using. MONyog 3.5 and earlier has an option called “Minimum interval between notifications” in Edit Server –> Notification Settings. MONyog generates alerts when this interval has elapsed. Newer versions of MONyog use a different concept: Counters are checked at every data collection, and alerts are sent immediately if a counter's value is above the threshold for a specified number of counts (specified by the option Edit Server –> Notification Settings : “Notify when alert-able _____ times”). Subsequent alerts for the same event are sent after another specified number of counts (specified by the option Edit Server –> Notification Settings : “Notify again after every _____ alert-able cycles”), to a max of 4 alerts.

2. MONyog sends them all in one e-mail itself.

3. Alerts for % of refused connections from MONyog means that MONyog was able to connect to the MySQL server successfully, and that the MySQL server was refusing too many other (not MONyog's) connections (perhaps because of invalid credentials, or an attempt at hacking?).

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