Developer Area/Common issues

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Revision as of 11:19, 12 May 2022 by Robertl (talk | contribs)

Elastic search triggers not dropped properly

At the moment we use DB triggers for elastic search updates, but we're looking into a better alternative. While we're working on it, some people might have this problem.


DB postgres. Having elastic search set up on the site. While running cron, we have an error that looks like this: -5: ERROR: trigger "search_elasticsearch_interaction_forum_post" for relation "interaction_forum_post" already exists] in EXECUTE("CREATE TRIGGER "search_elasticsearch_interaction_forum_post" BEFORE INSERT OR UPDATE OR DELETE ON "interaction_forum_post"

This means the cron got stuck while trying to drop/re-create the triggers.


We need to manually remove the trigger that was not dropped. And also check if we need to delete the record in pg_depend table.

  1. search for the trigger name in pg_trigger table
select oid,tgname,tgfoid from pg_trigger where tgname ='search_elasticsearch_interaction_forum_post';
  1. with that result, if there's a record in pg_depend where pg_depend.refobjid=pg_trigger.tgfoid and pg_depend.objid=pg_trigger.oid, then delete it
  2. delete the trigger with name 'search_elasticsearch_interaction_forum_post'
This is how the tables should look like when everything's ok:
select oid,tgname,tgfoid from pg_trigger where tgname like '%elastic%';
  oid    |                   tgname                    |  tgfoid  
14471173 | search_elasticsearch_usr                    | 14471170
14471174 | search_elasticsearch_interaction_instance   | 14471170
14471175 | search_elasticsearch_interaction_forum_post | 14471170
14471176 | search_elasticsearch_group                  | 14471170
14471177 | search_elasticsearch_view                   | 14471170
14471178 | search_elasticsearch_artefact               | 14471171
14471179 | search_elasticsearch_view_artefact          | 14471172
14471180 | search_elasticsearch_block_instance         | 14471170
14471181 | search_elasticsearch_collection             | 14471170
select objid,refobjid from pg_depend where refobjid in (14471170,14471171,14471172);
  objid  | refobjid  
14471173 | 14471170 
14471174 | 14471170 
14471175 | 14471170 
14471176 | 14471170 
14471177 | 14471170 
14471178 | 14471171 
14471179 | 14471172 
14471180 | 14471170 
14471181 | 14471170 
select oid,proname from pg_proc where proname like '%elas%';
  oid    |                   proname                   
14471170 | search_elasticsearch_queue_trigger
14471171 | search_elasticsearch_queue_artefact_trigger
14471172 | search_elasticsearch_queue2_trigger

PDF export

Chrome / Chromium installed via Snap

When the PDF export process was implemented it worked in Ubuntu because Chromium Browser was installed via apt-get. But then later Chromium was installed via Snap or apt-get. And later still via Snap only.

If your system installs Chromium via snap then to get Chrome-php to work you will need to adjust a couple of things because Snap will only create folders in a /home/ dir path and www-data has it's default home directory in /var/www/

So to get around this problem we can update the home directory for 'www-data' user. But keep in mind you are changing the Ubuntu Apache defaults and it may break some things in your setup from working.


1) As 'root' user - create a new directory in /home/ called 'www-data' with the following permissions: 755 2) Go into the /home/www-data/ directory and create a new directory called 'snap' that is owned by 'www-data' and permissions: 755 3) Update the path to www-data home directory: sudo usermod -d /home/www-data www-data

You may need to restart the machine

Then when you try and do an export with Pdfexport active it should work!