Execution Cycle: LATM

This section describes processing of online transactions, defined as transactions that result from direct user interaction with a Lawson form.

The following diagram and table show the steps that occur behind the scenes when a user makes a request for online transaction processing.

Illustration: LATM execution cycle
Step # What is Happening
1 The HTTP client sends a message containing details about a transaction request to its shared memory segment.
2 The HTTP client sends a version of the message containing fewer details to LATM's inbound message queue. (The shorter message tells LATM the address of the shared memory contains detailed information.)
3 LATM's queue sends a message to LATM.
4 The HTTP client shared memory sends a message to LATM (details about request).
5 LATM sends a request to LA-RTS’s shared memory segment (details about the request).
6 LATM sends a request to LA-RTS’s message queue (request for service).
7 LACOBORTS reads the request in its queue.
8 LA-RTS reads the message in its shared memory.
A (9) LA-RTS places updated data in its shared memory.
B (10) LA-RTS sends a message to its message queue.
C (11)

LA-RTS' message queue sends a message to its database driver.

These steps are labelled A, B, C, D because they may repeat in a single transaction when multiple trips to the database are required.

D (12) LA-RTS' shared memory sends a message to its database driver.
E (13) LA-RTS' database driver sends a message to LA-RTS' shared memory.
F (14) LA-RTS' database driver sends a message to LA-RTS' message queue.
15 LA-RTS places a message in it its shared memory.
16 LA-RTS sends a message to LATM's inbound queue.
17 LATM's inbound queue sends a message to LATM.
18 LA-RTS shared memory ends a message to LATM.
19 LATM sends a message to the HTTP request shared memory.
20 LATM sends a message to the HTTP request message queue.
21 The HTTP request message queue sends a message to the client.
22 The HTTP request shared memory sends a "Processing Complete" message to the HTTP client.