NServiceBus.SqlServer 6.0.1, 5.0.3, and 4.3.2 - Patch releases available

Hi everyone,

We’ve just released NServiceBus.SqlServer 6.0.1, 5.0.3, and 4.3.2.

Fixed bug

#624 Contention on SQL Server latches for clustered index prevents transport from scaling

How to know if you are affected

Users reaching the upper limit of SQL server resources that want to scale the server up.


Scaling up SQL server that runs at high CPU levels (~75%) results in minimal (if any) increase in overall system throughput. Repeated execution of wait time statistics query:

SELECT session_id, wait_type, wait_time, wait_resource FROM sys.dm_exec_requests
WHERE session_id > 50 and wait_type = 'pagelatch_ex'

shows a single page (5:1:4144 in the listing below is just an example) contributing the most to the wait times on pagelatch_ex:

session_id wait_type              wait_time         wait_resource
---------- ---------------------- ---------------  ------------------------
60         PAGELATCH_EX           20               5:1:4144
75         PAGELATCH_EX           12               5:1:4144
79         PAGELATCH_EX           40               5:1:4144
80         PAGELATCH_EX           25               5:1:4144
81         PAGELATCH_EX           31               5:1:4144
82         PAGELATCH_EX           35               5:1:4144
84         PAGELATCH_EX           8                5:1:1234
87         PAGELATCH_EX           11               5:1:7867
89         PAGELATCH_EX           5                5:1:3321
71         PAGELATCH_EX           3                5:1:2188

Should you upgrade immediately

Users affected should upgrade immediately. Changes introduced result in less resource consumption. As a result, non-affected users are advised to upgrade during the next maintenance window to take advantage of better performance.

Users can perform the upgrade one endpoint at a time, starting with the high throughput parts of the system first. Index upgrade guide describes details of the procedure.

Where to get it

You can install the new versions from NuGet.

With thanks,
The team in Particular

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