Hi there, 

How would you define / explain a Host Queue to someone who is new to BizTalk ?

Warmest regards, 

Peter

Hi Peter,

Each host has a queue implemented as a table in the message box database. When a message is published to the message box, BizTalk determines which subscribers are interested in the message, and places the reference of the message in the queues of the relevant hosts. The word references it is really important here since the messages itself are going to be saved in another set of tables ( messageparts, parts  and fragments) and basically the host tables are just pointers to the Spool table.

Each hosts polls its own queue periodically to get any pending messages and acts on them i.e. either start a new instance or correlate to an existing instance, potentially rehydrating it.

Each time you set up a new BizTalk Host, this tables are going to be created in the MessageBox  So, basically, the first time you configure BizTalk server  the following set of tables are created for BizTalkServerApplicationHost (by default the first created host)

Refer some good articles around it for more understanding:

BizTalk Hosts

Host Queue Tables

Host Queues are Physical Container for your Host inside BizTalk Message Box Db. Whenever you create a new host instance it will create you certain set of tables BizTalkServer ApplicationQ, SuspendedQ and SheduledQ.

Its been well described by Agustn Mntaras in his blog post below .

http://blogs.msdn.com/b/amantaras/archive/2010/02/25/host-queue-tables.aspx

Thanks

Abhishek