From a9b6615286996d8f920172b25b4187b7038d7e16 Mon Sep 17 00:00:00 2001
From: crapStone <me@crapstone.dev>
Date: Mon, 5 Feb 2024 19:16:35 +0100
Subject: [PATCH] create a workaround to fix the oom problem
---
cli/flags.go | 6 +++++
server/cache/memory.go | 57 +++++++++++++++++++++++++++++++++++++++++-
server/startup.go | 2 +-
3 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/cli/flags.go b/cli/flags.go
index 097cf4f..09a6404 100644
--- a/cli/flags.go
+++ b/cli/flags.go
@@ -138,6 +138,12 @@ var (
Aliases: []string{"config"},
EnvVars: []string{"CONFIG_FILE"},
},
+ &cli.Uint64Flag{
+ Name: "memory-limit",
+ Usage: "maximum size of memory in bytes to use for caching, default: 512MB",
+ Value: 512 * 1024 * 1024,
+ EnvVars: []string{"MAX_MEMORY_SIZE"},
+ },
// ############################
// ### ACME Client Settings ###
diff --git a/server/cache/memory.go b/server/cache/memory.go
index 093696f..743b6d0 100644
--- a/server/cache/memory.go
+++ b/server/cache/memory.go
@@ -1,7 +1,62 @@
package cache
-import "github.com/OrlovEvgeny/go-mcache"
+import (
+ "runtime"
+ "time"
+ "github.com/OrlovEvgeny/go-mcache"
+ "github.com/rs/zerolog/log"
+)
+
+type Cache struct {
+ mcache *mcache.CacheDriver
+ memoryLimit uint64
+ lastCheck time.Time
+}
+
+// NewInMemoryCache returns a new mcache that can grow infinitely.
func NewInMemoryCache() ICache {
return mcache.New()
}
+
+// NewInMemoryCache returns a new mcache with a memory limit.
+// If the limit is exceeded, the cache will be cleared.
+func NewInMemoryCacheWithLimit(memoryLimit uint64) ICache {
+ return &Cache{
+ mcache: mcache.New(),
+ memoryLimit: memoryLimit,
+ }
+}
+
+func (c *Cache) Set(key string, value interface{}, ttl time.Duration) error {
+ now := time.Now()
+
+ // checking memory limit is a "stop the world" operation
+ // so we don't want to do it too often
+ if now.Sub(c.lastCheck) > (time.Second * 3) {
+ if c.memoryLimitOvershot() {
+ log.Debug().Msg("memory limit exceeded, clearing cache")
+ c.mcache.Truncate()
+ }
+ c.lastCheck = now
+ }
+
+ return c.mcache.Set(key, value, ttl)
+}
+
+func (c *Cache) Get(key string) (interface{}, bool) {
+ return c.mcache.Get(key)
+}
+
+func (c *Cache) Remove(key string) {
+ c.mcache.Remove(key)
+}
+
+func (c *Cache) memoryLimitOvershot() bool {
+ var stats runtime.MemStats
+ runtime.ReadMemStats(&stats)
+
+ log.Debug().Uint64("bytes", stats.HeapAlloc).Msg("current memory usage")
+
+ return stats.HeapAlloc > c.memoryLimit
+}
diff --git a/server/startup.go b/server/startup.go
index ffdabb7..3966938 100644
--- a/server/startup.go
+++ b/server/startup.go
@@ -79,7 +79,7 @@ func Serve(ctx *cli.Context) error {
// redirectsCache stores redirects in _redirects files
redirectsCache := cache.NewInMemoryCache()
// clientResponseCache stores responses from the Gitea server
- clientResponseCache := cache.NewInMemoryCache()
+ clientResponseCache := cache.NewInMemoryCacheWithLimit(ctx.Uint64("memory-limit"))
giteaClient, err := gitea.NewClient(cfg.Gitea, clientResponseCache)
if err != nil {