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Diffstat (limited to '')
| -rw-r--r-- | docs/sample_config.yaml | 18 | ||||
| -rw-r--r-- | docs/usage/configuration/config_documentation.md | 17 |
2 files changed, 33 insertions, 2 deletions
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index 03a0f6314c..05a3606da0 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -784,6 +784,24 @@ caches: # #cache_entry_ttl: 30m + # This flag enables cache autotuning, and is further specified by the sub-options `max_cache_memory_usage`, + # `target_cache_memory_usage`, `min_cache_ttl`. These flags work in conjunction with each other to maintain + # a balance between cache memory usage and cache entry availability. You must be using jemalloc to utilize + # this option, and all three of the options must be specified for this feature to work. + #cache_autotuning: + # This flag sets a ceiling on 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. + #max_cache_memory_usage: 1024M + + # This flag sets a rough target for the desired memory usage of the caches. + #target_cache_memory_usage: 758M + + # '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. + #min_cache_ttl: 5m + # Controls how long the results of a /sync request are cached for after # a successful response is returned. A higher duration can help clients with # intermittent connections, at the cost of higher memory usage. diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md index 2af1f284b1..ca44363105 100644 --- a/docs/usage/configuration/config_documentation.md +++ b/docs/usage/configuration/config_documentation.md @@ -1119,7 +1119,17 @@ Caching can be configured through the following sub-options: with intermittent connections, at the cost of higher memory usage. By default, this is zero, which means that sync responses are not cached at all. - +* `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. + * `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. + * `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. Example configuration: ```yaml @@ -1127,8 +1137,11 @@ caches: global_factor: 1.0 per_cache_factors: get_users_who_share_room_with_user: 2.0 - expire_caches: false sync_response_cache_duration: 2m + cache_autotuning: + max_cache_memory_usage: 1024M + target_cache_memory_usage: 758M + min_cache_ttl: 5m ``` ### Reloading cache factors |