[Plugin: BackWPup] Backup often gets stuck on “Create Backup Zip File…”; script doesn’t terminate

I am wondering if the issue goes further. I just ran a manual backup and watched the process from SSH. Using top -c, I see that a PHP process is spawned to run the backup but it doesn’t exit once the job is complete. This could be something to do with running the plugin when using PHP as a CGI.

I contacted DreamHost support about this and the tech thinks that the zip process is being killed by their procwatch daemon because it uses too much memory. He suggested optimizing the script to use less RAM; however, I don’t know if that’s possible without writing a from-scratch implementation, which could be far more trouble than it’s worth.

I think we both may be having the same problem. Mine shows up in a Windows 2008 Web Server, using PHP5 with FastCGI. My related post is here. Please, have a look. We may be able to help each other with testing for a solution. I think this could very well be, as you suggest, a memory exhaustion problem. That would be, I think, easier to solve than fixing/getting PclZip fixed.

I’ve subscribed to your related thread, carlosman.

There are only two ways I can think of to combat memory exhaustion: Increase available memory, or reduce memory usage. Increasing available memory doesn’t seem to be an option in my situation, since DreamHost’s shared servers have an undisclosed hard limit. Decreasing usage would be more feasible, but it would require rewriting PclZip to optimize its usage or finding a new ZIP library.

I’ll look into the other options for PHP ZIP libraries.

Hello,

in my Plugin i use the option PCLZIP_OPT_ADD_TEMP_FILE_ON from PCLZIP to reduse the memory usage. normely it needs no more as 10MB of Memory to crate the zip file.
The creation of the file list can take many memory if thre a very lot of files.

I can’t take a other zip lib because the makes the compressen complete in the memory.

I have changed th file list generation a littel bit. now pclzip must not convert it again. IT needs more memory on generation. but i must dont use the add method for the databases dump file to add it to zip.
pleace test it again with the dev. version.

Tried for the last few days; just let my schedule run as usual. Jobs don’t seem to be getting killed any more; the logs appear to now end normally. I think it’s fixed! Marking this thread as resolved; will reopen if the bug comes back.

Thank you so much!

Incidentally, is it BackWPup that created these pclzip-13hexcharhash.gz files in my domain root? I can’t think of any other plugin I use (list on this page) that might have created those.

Thanks for the feadback.

Normely the temp folder for PCLZIP Temp files ist set to wp-content/backupwp folder and PCLZIP wil delete them after use.

I was having this issue less, and then I updated to 0.8.0 and now it seems that, once again, most daily backup jobs just continue to spin into eternity until the next day’s run supersedes them. (Was going to “unresolve” this topic, but—my apologies—I never “resolved” it in the first place. My mistake.)

Confirmed. Since the upgrade, not a single backup job has completed. The textfile logs are empty, and the job list says the last success was 2010-03-31.

Please update to 0.8.1 ther you kan make error log for pclzip too.

The last success is still 2010-03-31.

I’ve watched the process from SSH using top -c and watched as the PHP process (an instance of php5.cgi on DreamHost) ramps up its memory usage until it is killed by a monitoring script. It never gets to the point of generating much of a log, except for a list of all the files it’s adding.

I don’t think there’s anything you can do except reduce the memory usage, which would mean switching to a different compression library. PclZip uses in-memory compression to minimize the usage of temporary files; a library that uses temp files might work better on systems that limit memory usage.

Edit: Also, perhaps another compression format like GZip would have better luck.

I also think switching to another compression format is a must.

did you now a libiery for GZip that not works in memory ?
PclZip uses 8 MB of Memory and uses temp files.

good news for you….
backwpup now supports (in dev. version) tar.gz and tar and tar.bz2 Archives.

PLease test the development Version and give feadback.