Sql-server – SQL Server ReadOnly Routing Connection String

availability-groupshigh-availabilitysql serversql-server-2016

Can we route read-only connection to readable secondary replica without setting connection string (ApplicationIntent = ReadOnly)?

Best Answer

You would be required to set the Secondary Replica Copy as Readable, different from Read-Intent, and point the connection string to the actual instance where the replica resides.

This is not advisable, as it negates the HA usability of any Read-Intent replicas during failover.

Related Solutions

Sql-server – ApplicationIntent=ReadOnly Traffic when no Readable Secondary Available

There are several steps to configuring a server to accept ReadOnly traffic. The following link walks you through it, http://msdn.microsoft.com/en-us/library/hh710054.aspx ,but basically you need to configure each server in the AG and then set up the routing for each.

Here's the T-SQL involved:

ALTER AVAILABILITY GROUP [AG1]
 MODIFY REPLICA ON
N'COMPUTER01' WITH 
(SECONDARY_ROLE (ALLOW_CONNECTIONS = READ_ONLY));
ALTER AVAILABILITY GROUP [AG1]
 MODIFY REPLICA ON
N'COMPUTER01' WITH 
(SECONDARY_ROLE (READ_ONLY_ROUTING_URL = N'TCP://COMPUTER01.contoso.com:1433'));

ALTER AVAILABILITY GROUP [AG1]
 MODIFY REPLICA ON
N'COMPUTER02' WITH 
(SECONDARY_ROLE (ALLOW_CONNECTIONS = READ_ONLY));
ALTER AVAILABILITY GROUP [AG1]
 MODIFY REPLICA ON
N'COMPUTER02' WITH 
(SECONDARY_ROLE (READ_ONLY_ROUTING_URL = N'TCP://COMPUTER02.contoso.com:1433'));

ALTER AVAILABILITY GROUP [AG1] 
MODIFY REPLICA ON
N'COMPUTER01' WITH 
(PRIMARY_ROLE (READ_ONLY_ROUTING_LIST=('COMPUTER02','COMPUTER01')));

ALTER AVAILABILITY GROUP [AG1] 
MODIFY REPLICA ON
N'COMPUTER02' WITH 
(PRIMARY_ROLE (READ_ONLY_ROUTING_LIST=('COMPUTER01','COMPUTER02')));
GO

Sounds like you may be missing the configuration and/or routing information for the primary.

Sql-server – SQL SERVER – “ApplicationIntent=ReadOnly”Listener redirect to fully qualified domain name

My initial suspicion is that the initial setup didn't include the fully qualified name, but check for certain with the following statement:

SELECT ag.NAME AS "Availability Group"
    ,ar.replica_server_name AS "When Primary Replica Is"
    ,rl.routing_priority AS "Routing Priority"
    ,ar2.replica_server_name AS "RO Routed To"
    ,ar.secondary_role_allow_connections_desc
    ,ar2.read_only_routing_url
FROM sys.availability_read_only_routing_lists rl
INNER JOIN sys.availability_replicas ar ON rl.replica_id = ar.replica_id
INNER JOIN sys.availability_replicas ar2 ON rl.read_only_replica_id = ar2.replica_id
INNER JOIN sys.availability_groups ag ON ar.group_id = ag.group_id
ORDER BY ag.NAME
    ,ar.replica_server_name
    ,rl.routing_priority

The query was gratuitously lifted from this MSDN blog: https://blogs.msdn.microsoft.com/alwaysonpro/2014/01/22/modifying-alwayson-read-only-routing-lists/

In addition, make sure your JDBC driver supports the ApplicationIntent=ReadOnly parameter.

Best Answer

Related Solutions

Sql-server – ApplicationIntent=ReadOnly Traffic when no Readable Secondary Available

Sql-server – SQL SERVER – “ApplicationIntent=ReadOnly”Listener redirect to fully qualified domain name

Related Question