This guide gives information about how the polling system works in Ozeki NG SMS
Gateway database user. The information provided can help in controling and modifying
the behaviour.
Default operation
By default the system works the following way:
You insert your messages into the Ozekimessageout datase table with the status of "send"
The Ozeki software reads these messages with an SQL select command and updates the
status to "sending"
After the status is updated to "sending", the Ozeki software puts these messages
into the outbox queue.
The Ozeki SMS engine, takes the messages from the outbox queue and sends it
to the mobile network.
If the mobile network confirms, that it accepted the message for delivery, the status of
the message in the databse table is changed to "sent"
If the mobile network rejects the message for any reason (e.g. there is no money on the subscription),
the status is updated to "notsent".
After the mobile network accepted the message for delivery, it tries to deliver
the SMS to the recipient mobile phone. If the SMS reaches the mobile phone, a delivery
report is returned to the Ozeki NG software by the mobile network. When the delivery
report is received, the Ozeki NG software updates the database record to "delivered" status.
Please note, that it might be possible, that the delivery report comes in after several hours,
or sevaral days. This can happen for example if the recipient mobile phone is switched off.
In some cases the mobile network will not be able to deliver the SMS to the
recipient phone. For example if the recipient phone is never switched on. In this case
it will send an error report to Ozeki NG. If Ozeki NG receives this error report,
it will update the status of the database record to "undelivered" in the ozekimessageout
table.
What is polling and how does it work?
The term polling refers to the fact, that Ozeki NG must check the ozekimessagout
database table periodically for outgoing messages. The default polling mechnaism
works the following way:
Ozeki NG SMS Gateway executes an SQL SELECT statement on the database every
10 seconds (This is the polling interval). If it finds outgoing messages in the
database table, it will take out a maximum of 10 messages for delivery (this is the
maximum polling count). If the number of available messages for sending in the ozekimessagout
database table is less then the maximum polling count, the software assumes that
there are no more messages waiting to be sent, and will wait another 10 sec before
checking again for new messages. If the number of available messages for sending
in the ozekimessagout database table is more then the size of the maximum polling
count, the software will execute another poll on the database immediately after the
first poll is finished. This means that you don't have to worry about the length
of the polling interval. If there are messages in the database the Ozeki software
will read them as fast as possible.
Controling the maximum outbox size?
In some cases it might be possible, that there are several thousands, or even millions
of messages waiting to be sent in your ozekimessageout database table. In this
case you probably don't want Ozeki NG to take all of them at once. To control
the maximum number of messages in the Ozeki outbox, you can adjust the "MaxQueueSize"
parameter in the C:\Program Files\Ozeki\OzekiNG - SMS Gateway\config\user-sql1.txt
configuration file. Note that after adjusting this parameter, you will have
to restart the Ozeki NG service.
If you adjust this parameter, Ozeki NG SMS Gateway will suspend polling temporarily
if the outbox level reaches the specified limit. It will resume polling as soon
as the outbox level goes bellow 80% of the specified limit.
