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All MySQL DBs limited to max 3 concurrent/idle connections

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Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
This commit is contained in:
Shlomi Noach 2021-02-18 10:44:47 +02:00
parent 4a36e246c0
commit 710c9ddda5
2 changed files with 20 additions and 15 deletions
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7
go/logic/throttler.go
View File

@ -188,9 +188,12 @@ func (this *Throttler) collectControlReplicasLag() {
dbUri := connectionConfig.GetDBUri("information_schema")
var heartbeatValue string
if db, _, err := mysql.GetDB(this.migrationContext.Uuid, dbUri); err != nil {
db, _, err := mysql.GetDB(this.migrationContext.Uuid, dbUri)
if err != nil {
return lag, err
} else if err = db.QueryRow(replicationLagQuery).Scan(&heartbeatValue); err != nil {
}
if err := db.QueryRow(replicationLagQuery).Scan(&heartbeatValue); err != nil {
return lag, err
}

28
go/mysql/utils.go
View File

@ -18,8 +18,11 @@ import (
"github.com/outbrain/golib/sqlutils"
)
const MaxTableNameLength = 64
const MaxReplicationPasswordLength = 32
const (
MaxTableNameLength = 64
MaxReplicationPasswordLength = 32
MaxDBPoolConnections = 3
)
type ReplicationLagResult struct {
Key InstanceKey
@ -39,23 +42,22 @@ func (this *ReplicationLagResult) HasLag() bool {
var knownDBs map[string]*gosql.DB = make(map[string]*gosql.DB)
var knownDBsMutex = &sync.Mutex{}
func GetDB(migrationUuid string, mysql_uri string) (*gosql.DB, bool, error) {
func GetDB(migrationUuid string, mysql_uri string) (db *gosql.DB, exists bool, err error) {
cacheKey := migrationUuid + ":" + mysql_uri
knownDBsMutex.Lock()
defer func() {
knownDBsMutex.Unlock()
}()
defer knownDBsMutex.Unlock()
var exists bool
if _, exists = knownDBs[cacheKey]; !exists {
if db, err := gosql.Open("mysql", mysql_uri); err == nil {
knownDBs[cacheKey] = db
} else {
return db, exists, err
if db, exists = knownDBs[cacheKey]; !exists {
db, err = gosql.Open("mysql", mysql_uri)
if err != nil {
return nil, false, err
}
db.SetMaxOpenConns(MaxDBPoolConnections)
db.SetMaxIdleConns(MaxDBPoolConnections)
knownDBs[cacheKey] = db
}
return knownDBs[cacheKey], exists, nil
return db, exists, nil
}
// GetReplicationLagFromSlaveStatus returns replication lag for a given db; via SHOW SLAVE STATUS