From 8eed763b97acc3af6420f7e370c3e61ecc7befe2 Mon Sep 17 00:00:00 2001
From: LazyDBA247-Anyvision <yonin@anyvision.co>
Date: Thu, 14 Jan 2021 08:14:21 +0200
Subject: [PATCH 1/2] better mysql connection pool management

adding SetConnMaxLifetime configuration (https://golang.org/pkg/database/sql/#DB.SetConnMaxLifetime)
to enable refresh of connections.
---
 weed/command/scaffold.go        | 1 +
 weed/filer/mysql/mysql_store.go | 6 ++++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/weed/command/scaffold.go b/weed/command/scaffold.go
index f43a9d143..887c9883f 100644
--- a/weed/command/scaffold.go
+++ b/weed/command/scaffold.go
@@ -118,6 +118,7 @@ password = ""
 database = ""              # create or use an existing database
 connection_max_idle = 2
 connection_max_open = 100
+connection_max_lifetime_seconds = 0
 interpolateParams = false
 
 [postgres] # or cockroachdb
diff --git a/weed/filer/mysql/mysql_store.go b/weed/filer/mysql/mysql_store.go
index 5bc132980..62b9b287a 100644
--- a/weed/filer/mysql/mysql_store.go
+++ b/weed/filer/mysql/mysql_store.go
@@ -35,12 +35,13 @@ func (store *MysqlStore) Initialize(configuration util.Configuration, prefix str
 		configuration.GetString(prefix+"database"),
 		configuration.GetInt(prefix+"connection_max_idle"),
 		configuration.GetInt(prefix+"connection_max_open"),
+		configuration.GetInt(prefix+"connection_max_lifetime_seconds"),
 		configuration.GetBool(prefix+"interpolateParams"),
 	)
 }
 
-func (store *MysqlStore) initialize(user, password, hostname string, port int, database string, maxIdle, maxOpen int,
-	interpolateParams bool) (err error) {
+func (store *MysqlStore) initialize(user, password, hostname string, port int, database string, maxIdle, maxOpen,
+    maxLifetimeSeconds int,	interpolateParams bool) (err error) {
 	//
 	store.SqlInsert = "INSERT INTO filemeta (dirhash,name,directory,meta) VALUES(?,?,?,?)"
 	store.SqlUpdate = "UPDATE filemeta SET meta=? WHERE dirhash=? AND name=? AND directory=?"
@@ -65,6 +66,7 @@ func (store *MysqlStore) initialize(user, password, hostname string, port int, d
 
 	store.DB.SetMaxIdleConns(maxIdle)
 	store.DB.SetMaxOpenConns(maxOpen)
+	store.DB.SetConnMaxLifetime(maxLifetimeSeconds*time.Second)
 
 	if err = store.DB.Ping(); err != nil {
 		return fmt.Errorf("connect to %s error:%v", sqlUrl, err)

From 5581d087021560a4b83cf6434726c00c668abb75 Mon Sep 17 00:00:00 2001
From: LazyDBA247-Anyvision <yonin@anyvision.co>
Date: Thu, 14 Jan 2021 09:48:12 +0200
Subject: [PATCH 2/2] K8S mysql connection pool

set max lifetime to 10 minutes, keeping connection "fresh"
and eliminating mysql/memsql closing old connection (causing filer errors)
---
 k8s/seaweedfs/values.yaml | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/k8s/seaweedfs/values.yaml b/k8s/seaweedfs/values.yaml
index cdb9437ee..e08731354 100644
--- a/k8s/seaweedfs/values.yaml
+++ b/k8s/seaweedfs/values.yaml
@@ -298,8 +298,10 @@ filer:
     WEED_MYSQL_HOSTNAME: "mysql-db-host"
     WEED_MYSQL_PORT: "3306"
     WEED_MYSQL_DATABASE: "sw_database"
-    WEED_MYSQL_CONNECTION_MAX_IDLE: "10"
-    WEED_MYSQL_CONNECTION_MAX_OPEN: "150"
+    WEED_MYSQL_CONNECTION_MAX_IDLE: "5"
+    WEED_MYSQL_CONNECTION_MAX_OPEN: "75"
+    # "refresh" connection every 10 minutes, eliminating mysql closing "old" connections
+    WEED_MYSQL_CONNECTION_MAX_LIFETIME_SECONDS: "600"
     # enable usage of memsql as filer backend
     WEED_MYSQL_INTERPOLATEPARAMS: "true"
     WEED_LEVELDB2_ENABLED: "false"