Temporary message store for multi-part SMSs

Hi.

I'm using kannel talking SMPP to an upstream SMSC provider.

We can send and receive SMS fine, and DLR is working well too.  We use MySQL 
for the DLR store.

However, we have a High-Availability setup, which means that we have two 
machines running kannel, each with a connection to the upstream provider, and 
inbound SMSs can arrive on either connection.

In the case of multi-part SMSs, different parts can arrive on each link, 
resulting in one of our kannel instances having, say, parts 1 and 3, and the 
other instance having part 2 of the same message.  There's no way either of 
them can know what the other has seen, so the end result is that the user 
receives three independent message parts (not necessarily even in the right 
order).

Since we use a MySQL cluster for the DLR store, I wanted to use that also for 
the temporary message store for multi-part SMSs, and indeed I notice in the 
section "Compiling the Gateway" of 
https://kannel.org/download/1.4.5/userguide-1.4.5/userguide.html that there 
are two options (amongst others):

	--with-mysql	Enable using MySQL libraries for DBPool and DLR support.

	--with-redis	Enable using Redis for DBPool and DLR support. Requires 
the hiredis library.

I'm assuming that "DBPool" refers to the temporary message store during 
processing of multi-part SMSs.  I don't see the term "DBPool" defined or indeed 
even used anywhere in the documentation other than in the description of these 
options (and the related MSSQL etc options).


However, under "Core configuration", the option "store-type" says "This 
variable defines a type of backend used for store subsystem. Now two types are 
supported: a) file: writes store into one single file b) spool: writes store 
into spool directory (one file for each message) c) redis: writes store into a 
redis key storage."

I'm assuming that "two" in the above description is simply a hang-over from a 
previous version of the documentation, when the "redis" type was not 
available, but my main question is "how do we select MySQL for the DBPool 
storage?"


Thanks for any pointers...


Antony.

-- 
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 - Billy Connolly

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