You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Copy file name to clipboardExpand all lines: articles/reliability/reliability-azure-database-postgresql.md
+6-6Lines changed: 6 additions & 6 deletions
Display the source diff
Display the rich diff
Original file line number
Diff line number
Diff line change
@@ -77,7 +77,7 @@ When you select the fallback checkbox, the system creates the standby server in
77
77
- Periodic maintenance activities such as minor version upgrades happen at the standby first. To reduce downtime, the standby is promoted to primary so that workloads can keep on while the maintenance tasks are applied on the remaining node.
78
78
79
79
> [!NOTE]
80
-
> To ensure high availability functions properly, configure the `max_replication_slots` and `max_wal_senders` server parameter values. High availability requires four of each to handle failovers and seamless upgrades. For a high availability setup with 5 read replicas and 12 logical replication slots, set both `max_replication_slots` and `max_wal_senders` parameter values to 21. This configuration is necessary because each read replica and logical replication slot requires one of each, plus the four needed for high availability to function properly. For more information about `max_replication_slots` and `max_wal_senders` parameters, refer to the [documentation](/azure/postgresql/flexible-server/server-parameters-table-replication-sending-servers).
80
+
> To ensure high availability functions properly, configure the `max_replication_slots` and `max_wal_senders` server parameter values. High availability requires four of each to handle failovers and seamless upgrades. For a high availability setup with five read replicas and 12 logical replication slots, set both `max_replication_slots` and `max_wal_senders` parameter values to 21. This configuration is necessary because each read replica and logical replication slot requires one of each, plus the four needed for high availability to function properly. For more information about `max_replication_slots` and `max_wal_senders` parameters, refer to the [documentation](/azure/postgresql/flexible-server/server-parameters-table-replication-sending-servers).
81
81
82
82
### Monitor high-availability health
83
83
@@ -109,7 +109,7 @@ For a detailed guide on configuring and interpreting HA health statuses, see [Hi
109
109
110
110
- Planned events such as scale computing and scale storage happen on the standby first and then on the primary server. Currently, the server doesn't failover for these planned operations.
111
111
112
-
- If logical decoding or logical replication is configured on an HA-enabled flexible server.
112
+
- If you configure logical decoding or logical replication on an HA-enabled flexible server:
113
113
- In **PostgreSQL 16** and earlier, logical replication slots aren't preserved on the standby server after a failover by default.
114
114
- To ensure logical replication continues to function after failover, you need to enable the `pg_failover_slots` extension and configure supporting settings such as `hot_standby_feedback = on`.
115
115
- Starting with **PostgreSQL 17**, slot synchronization is supported natively. If you enable the correct PostgreSQL configurations (`sync_replication_slots`, `hot_standby_feedback`), logical replication slots are preserved automatically after failover, and no extension is required.
@@ -121,9 +121,9 @@ For a detailed guide on configuring and interpreting HA health statuses, see [Hi
121
121
122
122
### SLA
123
123
124
-
- The **Zonal** model offers an uptime for an [SLA for about 99%](https://azure.microsoft.com/support/legal/sla/postgresql).
124
+
- The **Zonal** model offers an uptime for an [SLA for about 99.95%](https://azure.microsoft.com/support/legal/sla/postgresql).
125
125
126
-
- The **Zone-redundancy** model offers an uptime for an [SLA for about 99%](https://azure.microsoft.com/support/legal/sla/postgresql).
126
+
- The **Zone-redundancy** model offers an uptime for an [SLA for about 99.99%](https://azure.microsoft.com/support/legal/sla/postgresql).
127
127
128
128
### Create an Azure Database for PostgreSQL with availability zone enabled
129
129
@@ -137,7 +137,7 @@ To learn how to enable or disable high availability configuration in your flexib
137
137
138
138
#### Transaction completion
139
139
140
-
Application transaction-triggered write and commits first log to the WAL on the primary server. The primary server streams these logs to the standby server by using the Postgres streaming protocol. When the standby server storage persists the logs, the primary server acknowledges write completion. The application commits its transaction only after this acknowledgment. This extra round-trip adds latency to your application. The impact percentage depends on the application. This acknowledgment process doesn't wait for the logs to be applied to the standby server. The standby server stays in recovery mode until it's promoted.
140
+
An application transaction triggers a write and commit that first logs to the WAL on the primary server. The primary server streams these logs to the standby server by using the Postgres streaming protocol. When the standby server storage persists the logs, the primary server acknowledges write completion. The application commits its transaction only after this acknowledgment. This extra round-trip adds latency to your application. The impact percentage depends on the application. This acknowledgment process doesn't wait for the logs to be applied to the standby server. The standby server stays in recovery mode until it's promoted.
141
141
142
142
#### Health check
143
143
@@ -292,7 +292,7 @@ The following picture shows the transition between VM and storage failure.
292
292
293
293
## Cross-region disaster recovery and business continuity
294
294
295
-
If a region-wide disaster, Azure can provide protection from regional or large geography disasters with disaster recovery by making use of another region. For more information on Azure disaster recovery architecture, see [Azure to Azure disaster recovery architecture](../site-recovery/azure-to-azure-architecture.md).
295
+
If a region-wide disaster occurs, Azure can provide protection from regional or large geography disasters with disaster recovery by making use of another region. For more information on Azure disaster recovery architecture, see [Azure to Azure disaster recovery architecture](../site-recovery/azure-to-azure-architecture.md).
296
296
297
297
Flexible server provides features that protect data and mitigate downtime for your mission-critical databases during planned and unplanned downtime events. Built on top of the Azure infrastructure that offers robust resiliency and availability, flexible server offers business continuity features that provide fault-protection, address recovery time requirements, and reduce data loss exposure. As you architect your applications, consider the downtime tolerance - the recovery time objective (RTO), and data loss exposure - the recovery point objective (RPO). For example, your business-critical database requires stricter uptime than a test database.
0 commit comments