Can disk speed utility be run on production jira?

[Rahul Aich [Nagra]]

Hi

Iwant to know if the disk speed utility in this link below be run directly on live production instance with say 500 users online.

Do you think it may have an impact?

https://confluence.atlassian.com/display/JIRAKB/Testing+Disk+Access+Speed

Rahul

[Norman Abramovitz]

I would agree with Nic if this test was designed to test disk speed but it is actually testing file system access through the JDK/JRE on a single file through a single Java process  as I read the description.   The test is attempting to look what is going on with file system access caused by outside factors. The test is an indicator what might be an issue.  This test cannot give you a definitive answer.

The KB article is asking for the average speed to be looked at to get an idea if there are issues.

I would run the test on another machine like your development/staging environment to get an idea how long the test takes to run.   If the test  runs for a few minutes  I would consider about running it on a production system.  

There are many other factors that comes into play why you should not run this test as well and you need to consider all of them before running anything on a production system.

"This basic test will perform the open, read/write, close and delete operations 1000 times to a temporary file in the java.io.tmpdir directory for each measurement, reporting the results as in the assessment section below. This test is the closest we can get to simulating the performance of a Java process when it comes to accessing the file system, allowing it to be an accurate measurement for JIRA's performance when utilising the disk. Other disk measurement tools may provide different results if they do not measure the specific performance of the Java JDK/JRE."

This tool has been designed primarily to perform basic disk assessment of Java running on the operating system, not the actual speed of the disk itself. It is highly possible a very fast disk can run Java slowly due to OS-level issues. This is not a substitute for a full disk analysis software suite and if the disk appears to be experiencing hardware issues or is slow, please raise this with the System Administrator or hosting provider of the server.

When reviewing the benchmark results:

• Focus primarily on the average result.
• When the open & close speeds are bad and the r/w is good, the likely cause is anti-virus.
• Open and close are important values as JIRA will access the indexes very often - the average search will close a file many times.
• A high minimum and average speed may be indicative of a low speed disk or hardware fault.
• If a disk has a high average and low minimum speed, there may be an environmental factor at play (see below for further information).

[Nic Brough -Adaptavist-]

I wouldn't do it.  Your results will be pretty useless if you do.

The point of a disk speed test is that you know what you're testing.  If you have other activity on the disk (such as JIRA being used) you have no idea how to remove the effects of your users from your tests.

While I wouldn't recommend it because you may slow down JIRA for your users, the main reason for not doing it is simply that it'll give you completely useless data.