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| -rw-r--r-- | README.rst | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/README.rst b/README.rst index 39a338c790..8a745259bf 100644 --- a/README.rst +++ b/README.rst @@ -565,4 +565,21 @@ sphinxcontrib-napoleon:: Building internal API documentation:: python setup.py build_sphinx - \ No newline at end of file + + + +Halp!! Synapse eats all my 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 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. 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. + |