On 2021-12-17 15:25:31, Batanun B wrote: > Thanks. I have thought about that too. But I think we might want to include > non-error transactions as well. I mean, with the problems this post is about > we want to see when the cached version of the start page was generated and > when it was last served from cache successfully. But maybe we could have a > permanent logging just for the start page, regardless of http status. That > should hopefully reduce the logging intensity enough so that logging to disk > isn't effecting the Varnish performance.
Well, it depends on the performance of your storage and the amount of req/sec on the front page, but these logs can get very huge very quickly. I'd suggest to determine the correct delivery of the front page via an external monitoring (e.g. icinga2 or a simple script). As far as I understand, you don't need to know the exact request, but more of a rough point in time of when the requests start failing. So a monitoring script which curls every minute should be sufficient and causes a lot less trouble. > One thing though... If you log all "status: 500+" transactions to disk, isn't > there a risk that your logging might exacerbate a situation where your site is > overwhelmed with traffic? Where a large load causes your backends to start > failing, and that triggers intense logging of those erroneous transactions > which might reduce the performance of Varnish, causing more timeouts etc which > cause more logging and so on... Indeed there is a risk of self-reinforcing effects, but it didn't happen yet. We also do not plan to logging 500s forever, but only till our problem is solved, which is an error in varnishs memory handling. At the moment, our most concerning 500s are caused by varnish itself, stating "Could not get storage", when the configured memory limit is reached. -- Mit freundlichen Grüßen Marco Dickert Administration und Technik evolver services GmbH Fon +49 / (0)3 71 / 4 00 03 78 24 Fax +49 / (0)3 71 / 4 00 03 79 E-Mail [email protected] Web https://www.evolver.de Sitz der Gesellschaft: Chemnitz Handelsregister: Amtsgericht Chemnitz, HRB 22649 Geschäftsführer: Torsten Gramann und Mathias Möckel _______________________________________________ varnish-misc mailing list [email protected] https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc
