From 2184f61faeb5ce88c05d28913e3f881813c0c5dd Mon Sep 17 00:00:00 2001 From: Aaron Raimist Date: Wed, 29 Jul 2020 09:35:44 -0500 Subject: Various improvements to the docs (#7899) --- debian/changelog | 10 ++++++++++ debian/matrix-synapse.default | 2 +- debian/synctl.ronn | 27 ++++++++++++++------------- 3 files changed, 25 insertions(+), 14 deletions(-) (limited to 'debian') diff --git a/debian/changelog b/debian/changelog index 3825603ae4..99165b61fd 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,3 +1,13 @@ +matrix-synapse-py3 (1.xx.0) stable; urgency=medium + + [ Synapse Packaging team ] + * New synapse release 1.xx.0. + + [ Aaron Raimist ] + * Fix outdated documentation for SYNAPSE_CACHE_FACTOR + + -- Synapse Packaging team XXXXX + matrix-synapse-py3 (1.17.0) stable; urgency=medium * New synapse release 1.17.0. diff --git a/debian/matrix-synapse.default b/debian/matrix-synapse.default index 65dc2f33d8..f402d73bbf 100644 --- a/debian/matrix-synapse.default +++ b/debian/matrix-synapse.default @@ -1,2 +1,2 @@ # Specify environment variables used when running Synapse -# SYNAPSE_CACHE_FACTOR=1 (default) +# SYNAPSE_CACHE_FACTOR=0.5 (default) diff --git a/debian/synctl.ronn b/debian/synctl.ronn index a73c832f62..1bad6094f3 100644 --- a/debian/synctl.ronn +++ b/debian/synctl.ronn @@ -46,19 +46,20 @@ Configuration file may be generated as follows: ## ENVIRONMENT * `SYNAPSE_CACHE_FACTOR`: - Synapse's architecture is quite RAM hungry currently - a lot of - recent room data and metadata is deliberately cached in RAM in - order to speed up common requests. This will be improved in - future, but for now the easiest way to either reduce the RAM usage - (at the risk of slowing things down) is to set the - SYNAPSE_CACHE_FACTOR environment variable. Roughly speaking, a - SYNAPSE_CACHE_FACTOR of 1.0 will max out at around 3-4GB of - resident memory - this is what we currently run the matrix.org - on. The default setting is currently 0.1, which is probably around - a ~700MB footprint. You can dial it down further to 0.02 if - desired, which targets roughly ~512MB. Conversely you can dial it - up if you need performance for lots of users and have a box with a - lot of RAM. + 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 ``SYNAPSE_CACHE_FACTOR`` 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. + + 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. ## COPYRIGHT -- cgit 1.4.1