\fBsynctl\fR can be used to start, stop or restart Synapse server\. The control operation can be done on all processes or a single worker process\.
.SH"OPTIONS"
.TP
\fBaction\fR
The value of action should be one of \fBstart\fR, \fBstop\fR or \fBrestart\fR\.
.TP
\fBconfigfile\fR
Optional path of the configuration file to use\. Default value is \fBhomeserver\.yaml\fR\. The configuration file must exist for the operation to succeed\.
Synapse\'s architecture is quite RAM hungry currently \- we deliberately cache a lot of recent room data and metadata in RAM in order to speed up common requests\. We\'ll improve this in the future, but for now the easiest way to either reduce the RAM usage (at the risk of slowing things down) is to set the almost\-undocumented \fBSYNAPSE_CACHE_FACTOR\fR environment variable\. The default is 0\.5, which can be decreased to reduce RAM usage in memory constrained enviroments, or increased if performance starts to degrade\.
.IP
However, degraded performance due to a low cache factor, common on machines with slow disks, often leads to explosions in memory use due backlogged requests\. In this case, reducing the cache factor will make things worse\. Instead, try increasing it drastically\. 2\.0 is a good starting value\.
