I have started using Piwik for a project and I seem to have reached a ceiling on the number of custom variables. Does anyone know if there is a workaround?
If I follow the instructions to increase the number of variables (I first tried 100) the increase command appears to run without error. I then get a failure posting web hits via the API. (Apache error log).
I reduced the number of custom variables to 50 and it works ok.
Looking at the web logs I think the system is getting stuck around the 52 mark.
I notice behind the scenes a new column is added to the piwik_log_visit table for each custom variable configured.
eg…custom_var_v23,custom_var_v24,custom_var_v25…
My initial thoughts are that I am hitting a limit on the number of columns in the mysql table.
Does anyone have any experience, thoughts on this?
I’m using the latest piwik VM from bitnami.
Many Thanks
I got a bit further with this so thought I would post an update.
I couldn’t find much in the immediate log files but I looked through the PHP and tried the queries on the database manually.
You were correct when you mentioed the data limits. However there is a limit of the number of bytes per row that can be allocated. It seems that the row limit is hit at around 55 variables. If you run the customvariables:set-max-custom-variables 100
command you can see the index doesn’t go up in the output after about 55.
Running the alter table create column SQL manually produces this error.
Error Code: 1118. Row size too large. The maximum row size for the used table type, not counting BLOBs, is 65535. You have to change some columns to TEXT or BLOBs