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| -rw-r--r-- | changelog.d/12776.doc | 2 | ||||
| -rw-r--r-- | docs/usage/configuration/config_documentation.md | 13 |
2 files changed, 11 insertions, 4 deletions
diff --git a/changelog.d/12776.doc b/changelog.d/12776.doc new file mode 100644 index 0000000000..c00489a8ce --- /dev/null +++ b/changelog.d/12776.doc @@ -0,0 +1,2 @@ +Add additional info to documentation of config option `cache_autotuning`. + diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md index 525e1c7a91..0f5bda32b9 100644 --- a/docs/usage/configuration/config_documentation.md +++ b/docs/usage/configuration/config_documentation.md @@ -1130,14 +1130,19 @@ Caching can be configured through the following sub-options: * `cache_autotuning` and its sub-options `max_cache_memory_usage`, `target_cache_memory_usage`, and `min_cache_ttl` work in conjunction with each other to maintain a balance between cache memory usage and cache entry availability. You must be using [jemalloc](https://github.com/matrix-org/synapse#help-synapse-is-slow-and-eats-all-my-ramcpu) - to utilize this option, and all three of the options must be specified for this feature to work. + to utilize this option, and all three of the options must be specified for this feature to work. This option + defaults to off, enable it by providing values for the sub-options listed below. Please note that the feature will not work + and may cause unstable behavior (such as excessive emptying of caches or exceptions) if all of the values are not provided. + Please see the [Config Conventions](#config-conventions) for information on how to specify memory size and cache expiry + durations. * `max_cache_memory_usage` sets a ceiling on how much memory the cache can use before caches begin to be continuously evicted. They will continue to be evicted until the memory usage drops below the `target_memory_usage`, set in - the flag below, or until the `min_cache_ttl` is hit. - * `target_memory_usage` sets a rough target for the desired memory usage of the caches. + the setting below, or until the `min_cache_ttl` is hit. There is no default value for this option. + * `target_memory_usage` sets a rough target for the desired memory usage of the caches. There is no default value + for this option. * `min_cache_ttl` sets a limit under which newer cache entries are not evicted and is only applied when caches are actively being evicted/`max_cache_memory_usage` has been exceeded. This is to protect hot caches - from being emptied while Synapse is evicting due to memory. + from being emptied while Synapse is evicting due to memory. There is no default value for this option. Example configuration: ```yaml |