For the past week my site goes down SEVERAL times an hour. After doing several speed tests with webpagetest.org and pingdom, i notice TTFB at well over 30-45 seconds.
I've tried upping the php memory on my server (helped with the overall crashing but not the response times). I've tried turning off the plugins and meticulously turning them on one by one and rerunning hundreds of tests... and i've determined that the Defender plugin was causing all of my crashes/slowdowns.
Even attempts to disable the plugin once active would be met with unresponsive servers/ white screen of death.... i had to literally rename the plugin in order to disable it.