Error: Exception: Unable to obtain lock for session

[nbcommunication]

Hi,

I upgraded 100+ sites to the latest master on Friday, and we've gotten the following error email notification from a few of them over the weekend:

Umm… Error: Exception: Unable to obtain lock for session (retry in 30s) (in processwire/wire3/modules/Session/SessionHandlerDB/SessionHandlerDB.module line 96) 
User: ?, Version: 3.0.184

This is a new error, added in the latest master release: https://github.com/processwire/processwire/commit/7a2ff6c15dde8f6768676181bfbeeaefe4761b0b#diff-4c158c18e5f331d4e9ff8b27eff8ae2c4cd34d16f6d0f2b427aa36791637c64f

The session lock time is set to 50 seconds, I think this is the default, so I suspect the issue is on our end with our databases/server(s). 

I'm going to investigate further and try and figure out the issue and will update here if/when I do.

If anyone else has come across this or has any more info, please let me know!

Cheers,

Chris

[sodesign]

Hi Chris,

We're seeing the same thing after upgrading one of our sites - did you find out how to fix it?

Thanks,
Tom

[Clarity]

Hi Chris,

This error usually occurs when your page is loading too slowly (there might be many reasons of this). It's good to check the performance of the sites where the error occurs.

[nbcommunication]

Hi @sodesign,

Haven't found a workaround, but can confirm @Clarity's message above is correct. For us it happens on sites which are querying external APIs every so often and updating the site data based on the results.

Cheers,

Chris 

[sodesign]

Bizarrely disabling Tracy Debugger was what stopped the issue for us in the end. I probably just need to update the module.

Thanks for your help ?

[Clarity]

Glad if it helped!

[LAPS]

I confirm that disabling Tracy Debugger worked for me. I've installed latest (at the time of writing) version: 4.23.41

[gebeer]

can confirm same behaviour. Disabling TracyDebugger helps.

Fatal error: Exception: Unable to obtain lock for session (retry in 30s) (in xxx/wire/modules/Session/SessionHandlerDB/SessionHandlerDB.module line 96) #0 [internal function]: ProcessWire\SessionHandlerDB->read('836ab08de536179...') #1 xxx/wire/core/Session.php(327): session_start(Array) #2 xxx/wire/core/Wire.php(413): ProcessWire\Session->___init() #3 xxx/wire/core/WireHooks.php(952): ProcessWire\Wire->_callMethod('___init', Array) #4 xxx/wire/core/Wire.php(484): ProcessWire\WireHooks->runHooks(Object(ProcessWire\Session), 'init', Array) #5 xxx/wire/core/Session.php(205): ProcessWire\Wire->__call('init', Array) #6 xxx/wire/core/ProcessWire.php(581): ProcessWire\Session->__construct(Object(ProcessWire\ProcessWire)) #7 xxx/wire/core/ProcessWire.php(315): ProcessWire\ProcessWire->load(Object(ProcessWire\Config)) #8 xxx/index.php(52): ProcessWire\ProcessWire->__construct(Object(ProcessWire\Config)) #9 {main} in xxx/index.php on line 64

 

[snck]

Any news on this? I was also having this problem for a while now and disabling TracyDebugger helped a little, but the error messages still find their way to my mailbox. This is happening on a virtual server running PHP 8.1.27 and mariaDB 10.11.4 with PW 3.0.229.