Forum OpenACS Q&A: Re: Some thoughts on OpenACS caching

Posted by Gustaf Neumann on

I particularly like the -cache_keys parameter available

Well, the db_interface with "-cache_key" iis not a recommended interface, since this does not scale and leads to many locks. Flushing of this cache is brute-force or not happening at all. In the sketched case - as you noted -, the cache has to be flushed (in the full cluster) whenever a new package is enabled (or installed) or disabled.

If you do not care about getting proper results in these situations, one can use the version below on oacs-5-10, which will be a lock free cache (not flushed as well).

one proc that I noticed gets called a lot ...

Why is apm_get_installed_versions gets called a lot on your site. On stock instances, this is only called by the package installer...


  ad_proc -public apm_get_installed_versions {
  } {
     Sets the current installed version of packages installed on this system
     in an array keyed by package_key.
     @param array Name of array in caller's namespace where you want this set
 }  {
     upvar 1 $array installed_version
     array set installed_version [acs::per_thread_cache eval -key acs-tcl-apm_get_installed_versions {
        db_list_of_lists -cache_key installed_packages installed_packages { 
            select package_key, version_name
            from apm_package_versions
            where  enabled_p = 't'