Identify if it is AlloyDB and do not check the replication stats when it's a replica (readpool) instance

Author: ryanbooz

input/postgres/replication.go

@@ -80,10 +80,11 @@ func GetReplication(ctx context.Context, c *Collection, db *sql.DB) (state.Postg
 		return repl, err
 	}
 
-	// Skip follower statistics on Aurora for now - there might be a benefit to support this for monitoring
+	// Skip follower statistics on Aurora and AlloyDB for now - there might be a benefit to support this for monitoring
 	// logical replication in the future, but it requires a bit more work since Aurora will error out
-	// if you call pg_catalog.pg_current_wal_lsn() when wal_level is not logical.
-	if c.PostgresVersion.IsAwsAurora {
+	// if you call pg_catalog.pg_current_wal_lsn() when wal_level is not logical, and AlloyDB read
+	// pool replicas will error out on replication queries.
+	if c.PostgresVersion.IsAwsAurora || c.PostgresVersion.IsAlloyDB {
 		return repl, nil
 	}
 

input/postgres/version.go

@@ -32,6 +32,12 @@ func getPostgresVersion(ctx context.Context, db *sql.DB) (version state.Postgres
 	}
 	version.IsAwsAurora = isAwsAurora
 
+	isAlloyDB, err := GetIsAlloyDB(ctx, db)
+	if err != nil {
+		return
+	}
+	version.IsAlloyDB = isAlloyDB
+
 	err = db.QueryRowContext(ctx, QueryMarkerSQL+"SELECT pg_catalog.count(1) = 1 FROM pg_extension WHERE extname = 'citus'").Scan(&version.IsCitus)
 	if err != nil {
 		return
@@ -45,3 +51,9 @@ func GetIsAwsAurora(ctx context.Context, db *sql.DB) (bool, error) {
 	err := db.QueryRowContext(ctx, QueryMarkerSQL+"SELECT pg_catalog.count(1) = 1 FROM pg_settings WHERE name = 'rds.extensions' AND setting LIKE '%aurora_stat_utils%'").Scan(&isAurora)
 	return isAurora, err
 }
+
+func GetIsAlloyDB(ctx context.Context, db *sql.DB) (bool, error) {
+	var isAlloyDB bool
+	err := db.QueryRowContext(ctx, QueryMarkerSQL+"SELECT pg_catalog.count(1) >= 1 FROM pg_settings WHERE name LIKE 'alloydb.%'").Scan(&isAlloyDB)
+	return isAlloyDB, err
+}

state/postgres_version.go

@@ -23,6 +23,7 @@ type PostgresVersion struct {
 
 	// For collector use only, to avoid calling functions that don't work
 	IsAwsAurora bool // Amazon Aurora
+	IsAlloyDB   bool // Google AlloyDB for PostgreSQL
 	IsCitus     bool // Citus extension (e.g. with Azure CosmosDB for PostgreSQL)
 	IsEPAS      bool // EnterpriseDB Advanced Server
 }