Glassfish_logo.svgI manage a small application that is hosted on a single Linux virtual machine and have noticed some occasional performance and stability issues.

The server runs CentOS, MySQL and a GlassFish server. I chose GlassFish several years ago because at the time it was the only EJB3 container around, as well as being very well integrated with the NetBeans IDE.

Like most JavaEE containers, it also makes clustering and scaling easier. Continue reading

logoStashPNGI was having a problem where Stash (which was installed as a service) wasn’t starting up properly and giving me a page that made it look like there was a problem with the database.

I have a local MySQL on the same machine as the Stash server, and both that service and the Stash server are set to automatically start up. Continue reading

English: A timezone indicator showing UTC+6 Ру...

I support a web application that is hosted on a virtual private server. The application architecture is JavaEE running under GlassFish on CentOS.

Like most ISP’s, my hosting provider builds vanilla Linux boxes that can be configured with various flavors of the OS.

Out of the box these images have their timezone set to UTC, and since my end users are in California, and I’m not doing anything on the client to handle timezone conversion, the times that come up in the application are off by 7 or 8 hours (depending on whether it’s Daylight Savings time or not. Continue reading

Recently after an upgrade of my Plesk panel, my web site was down.

In fact ALL of the domains I host on that particular cloud server were not working. A quick call to 1and1’s server guys and it appeared that there was some step in the upgrade process that failed.

They had it fixed in a moment, and then went the extra step to send me the command to fix this myself in the future:

/usr/local/psa/admin/bin/httpdmng –reconfigure-all

That simple command reset all the server config files and got all of the domains working again.

A huge thanks to the 1and1 Server Support guys and Khristian Byrd specifically !!!

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The other day I got a notification from the Plesk control panel for Carticipate telling me that the user account was about to expire. I logged into Plesk only to find out that the disk on the VPS was full.

Now this was really confusing, since the entire Carticipate system consists of a web2py install, on Linux with a fairly small MySQL database, and the VPS had 20 gigabytes of disk space.

I looked around and found that there were three full backups each about 14Gb, with several incremental backups of a gig or so. Thinking this was the issue, I deleted all but the latest backup.

Well apparently, those backups are stored somewhere not on the server, so that made no difference to the space problem. So I did the next natural thing which was to look for big log files, clear out /tmp, and anything that might be causing the problem. I only managed to clear out a few megabytes of space.

I dug around some more and found a lot of files under the /root directory that seemed to be related to updating Plesk. Since that’s provided as part of my 1and1 VPS service, I called the support number to see whether they could help me figure out where my space had gone. Unfortunately, for the first time, they were not very helpful, suggesting that I needed to research and find out where the big files were on my system.

After some frustrating arguing with the support guy, where I pointed out that I couldn’t get support from Plesk, only they could, I finally gave up and went to my old stand by of Google.

First a quick search to find where the mysterious gigabytes of space were being consumed. First I did a quick “find” command with:

Going to a few of these folders and running “du -hs” gave me the folders that seemed to have a lot of files in them and were eating up a lot of space.

A few more searches on the Parallels site, and found a couple more references telling me that these were both OK to clean out.

The /root/psa folder is where Plesk was configured to download updates, and apparently it doesn’t clean out those folders after the update is successful.

The other folder is where all the dumps from the local backups get placed, and that was the primary problem area. The /var/lib/psa/dumps folder was over 14Gb of the 20Gb, so cleaning that out got me started again.

Looking at the dump directory, it appears to have daily dumps of all of the Plesk stuff going back forever, so this may happen again, but for now, my VPS backup is down to a much more reasonable 2Gb.