Cache

Use cache when Fluxheim sits in front of an origin and repeated responses should be served faster.

Proxy cache example

[cache]
enabled = true
default_ttl_secs = 300
max_object_bytes = "32MiB"
status_header = "X-Cache-Status"

[cache.memory]
enabled = true
max_size_bytes = "256MiB"

[cache.disk]
enabled = true
path = "/var/cache/fluxheim/site"
max_size_bytes = "10GiB"

Cache backends

backend	使う場面
`memory`	You need the fastest cache and can keep objects in RAM.
`disk`	You need cache capacity that survives process restarts.
`tiered`	hot objectsにはmemory、より大きなcapacityにはdiskが必要な場合。
`storage-bin`	high churnが予想され、bounded disk allocationが必要な場合。
`encrypted disk`	You need cache-at-rest protection for disk objects.

Route cache policy

[[vhosts.routes]]
name = "assets"
path_prefix = "/assets/"
action = "proxy"

[vhosts.routes.proxy]
upstreams = ["127.0.0.1:3000"]

[vhosts.routes.cache]
enabled = true
status_ttls = { "200" = 3600, "404" = 60 }
content_types = ["text/css", "application/javascript", "image/*"]
extensions = ["css", "js", "png", "webp", "svg"]
include_query = false
stale_while_revalidate_secs = 30
stale_if_error_secs = 120

Advanced cache controls

制御	目的
`lock`	Collapse concurrent misses so one request fills the cache.
`range.slice`	Cache fixed byte slices for large files and resumable downloads.
`peer_fill`	originを使う前に、あるedgeを別のedgeからfillできるようにします。
`origin_protection`	高負荷時のconcurrent origin fillsを制限します。
`cache_purger`	stale disk entriesをbounded batchesでcleanします。

Use cache carefully

Do not cache private user pages unless the route is explicitly safe.
Keep cache keys bounded and predictable.
contentが頻繁に変わる場合はpurgeまたは短いTTLを使います。
cookies、authorization、preview headers、unsafe query stringsではbypassします。