From f76e77341b5f8e98fc93726173a328eccd50c189 Mon Sep 17 00:00:00 2001
From: Garet Halliday <ghalliday@gfxlabs.io>
Date: Mon, 12 Sep 2022 18:14:39 -0500
Subject: [PATCH] allow multiple replicas
---
README.md | 4 ++--
lib/gat/gatling/conn_pool/conn_pool.go | 10 +++++-----
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/README.md b/README.md
index 11605e13..4bd71f57 100644
--- a/README.md
+++ b/README.md
@@ -21,8 +21,8 @@ PostgreSQL pooler (like PgBouncer) with sharding, load balancing and failover su
| Transaction pooling | :white_check_mark: | :white_check_mark: | Identical to PgBouncer. |
| Session pooling | :white_check_mark: | :white_check_mark: | Identical to PgBouncer. |
| `COPY` support | :white_check_mark: | :white_check_mark: | Both `COPY TO` and `COPY FROM` are supported. |
-| Query cancellation | :white_check_mark: | no | Supported both in transaction and session pooling modes. |
-| Load balancing of read queries | :white_check_mark: | no | Using random between replicas. Primary is included when `primary_reads_enabled` is enabled (default). |
+| Query cancellation | :white_check_mark: | :white_check_mark: | Supported both in transaction and session pooling modes. |
+| Load balancing of read queries | :white_check_mark: | :white_check_mark: | Using random between replicas. Primary is included when `primary_reads_enabled` is enabled (default). |
| Sharding | :white_check_mark: | no | Transactions are sharded using `SET SHARD TO` and `SET SHARDING KEY TO` syntax extensions; see examples below. |
| Failover | :white_check_mark: | no | Replicas are tested with a health check. If a health check fails, remaining replicas are attempted; see below for algorithm description and examples. |
| Statistics | :white_check_mark: | no | Statistics available in the admin database (`pgcat` and `pgbouncer`) with `SHOW STATS`, `SHOW POOLS` and others. |
diff --git a/lib/gat/gatling/conn_pool/conn_pool.go b/lib/gat/gatling/conn_pool/conn_pool.go
index 6f8fe055..74347af6 100644
--- a/lib/gat/gatling/conn_pool/conn_pool.go
+++ b/lib/gat/gatling/conn_pool/conn_pool.go
@@ -16,8 +16,8 @@ import (
)
type connections struct {
- primary *server.Server
- replica *server.Server
+ primary *server.Server
+ replicas []*server.Server
mu sync.Mutex
}
@@ -27,11 +27,11 @@ func (s *connections) choose(role config.ServerRole) *server.Server {
case config.SERVERROLE_PRIMARY:
return s.primary
case config.SERVERROLE_REPLICA:
- if s.replica == nil {
+ if len(s.replicas) == 0 {
// fallback to primary
return s.primary
}
- return s.replica
+ return s.replicas[rand.Intn(len(s.replicas))]
default:
return nil
}
@@ -141,7 +141,7 @@ func (c *ConnectionPool) chooseConnections() *connections {
case config.SERVERROLE_PRIMARY:
srvs.primary = srv
case config.SERVERROLE_REPLICA:
- srvs.replica = srv
+ srvs.replicas = append(srvs.replicas, srv)
}
}
if srvs.primary == nil {
--
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