In any non-trivial system, failure is inevitable and incidents happen. How we deal with the incidents aftermath determines if they just cost money or we gain something from them.
I am sure this has never happened to you, but try to imagine. Your on-call phone just got the message: The site is down! You open your Nagios dashboard and you are greeted by a sea of red. All Apache servers are not responding. The database…
This article “The four levels of resilience in systems” was published on my website…
I recently discovered, in our production database, that the query used to monitor free space in tablespaces was starting to show in Top SQL in performance monitoring, meaning it’s taking too much database time.We use a fairly standard query to…
We started using Hadoop, written in Java and it exposes it’s metrics thru JMX, which is a Java standard for monitoring and metrics publishing. Since we use Reconnoiter for all other metrics collection and graphing, I wanted to get this JMX data into it.Reconnoiter has a Java…
This is a second part of my previous article Collecting Oracle metrics with Reconnoiter.If you are using Database Resident Connection Pooling (DRCP) for connecting your application to Oracle Database (and if you are serious about scalability you should), then you…
Oracle database makes your life, as an operator, easier by measuring and providing tons of metrics. These metrics range from wait time counters, thru I/O operations and sizes to number of failed logins. Each new version adds even more useful metrics. For…
I’ve come across an interesting thing recently, that I didn’t think mattered, but, as I’m about to demonstrate, it does. So we all know about different levels of error reporting in PHP, right? We all know, that we must pay close attention to E_WARNING and…
Indices (or indexes, if you will) are always good, right? Well, Tom Kyte would disagree with you and so would I. In fact, indices will always impede data manipulation performance, so they should be used only where they are useful in queries. But determining if an index is…