IBM MQ: Introduction

I’ll start this blog with a piece of soft­ware I’ve been learn­ing in the past few months: IBM MQ. 

Mes­sage queu­ing is a dis­trib­uted inter-process com­mu­ni­ca­tion method based on mes­sage pass­ing. Typ­i­cal mes­sage queu­ing sys­tems have mech­a­nisms to ensure mes­sages are deliv­ered to their intend­ed des­ti­na­tion and that no mes­sages are lost dur­ing trans­mis­sion and reception.

IBM MQ itself is a mar­ket-proven prod­uct which has matured as the years went by. It’s now almost an indus­try stan­dard and it is used in many indus­tries, such as bank­ing, insur­ance and even the auto­mo­tive industry.

What is message queuing?

Sim­ply put, mes­sage queu­ing is the mech­a­nism which is used by appli­ca­tion to com­mu­ni­cate with each oth­er by using mes­sages. The mes­sages are usu­al­ly sent to a “mes­sage bro­ker” (not to be con­fused with IBM Infor­ma­tion Bro­ker, for­mer­ly, IBM Web­Sphere Mes­sage Bro­ker, which is an Enter­prise Ser­vice Bus).

The mes­sage bro­ker (in this case, IBM MQ) is respon­si­ble for stor­ing mes­sages while in tran­sit (option­al­ly stor­ing them to per­ma­nent stor­age for data recov­er­ing pur­pos­es) and guar­anties deliv­ery. It also has fea­tures which enables it to route mes­sages to sev­er­al des­ti­na­tions at once (in IBM MQ, this is called pub­lish and subscribe).

History

IBM MQ is the nat­ur­al evo­lu­tion of IBM’s mes­sag­ing prod­ucts. It all start­ed in the 1960s, when IBM released the IBM 7740 Com­mu­ni­ca­tion Con­trol Sys­tem and the IBM 7750 Pro­grammed Trans­mis­sion Con­trol. These were pro­gram­ma­ble mes­sage-switch­ing hard­ware prod­ucts, which enabled mes­sage-ori­ent­ed com­mu­ni­ca­tion between computers.

After, in 1971, IBM released TCAM (Telecom­mu­ni­ca­tions Access Method) for its S/360 fam­i­ly of com­put­er sys­tems, and­hav­ing adopt­ed CICS for trans­ac­tion man­age­ment, users want­ed a way to inte­grate TCAM with CICS.

These prod­ucts went through sev­er­al ver­sions and in 1992, IBM decid­ed to release IBM MQSeries, which incor­po­rat­ed an evo­lu­tion of the TCAM mes­sage-pass­ing engine. MQSeries was lat­er (in 2002) renamed to Web­Sphere MQ (because of its inte­gra­tion in the Web­Sphere prod­uct family).

The first MQSeries ver­sion for dis­trib­uted sys­tems (the first six releas­es were for the S/360 and AS/400 com­put­er sys­tems) was named MQSeries 2.0 and was avail­able for OS/2 and AIX. It was released in Feb­ru­ary 1995.

With ver­sion 8.0, IBM dropped the word ‘Web­Sphere’ from the name and released IBM MQ 8.0 in May 23rd 2014.

The cur­rent ver­sion is IBM MQ 9.1 and it was released on July 27th 2018. 

MQ Releases

IBM MQ is avail­able in two dif­fer­ent forms: Con­tin­u­ous Release and a Long Term Support.

Long Term Sup­port releas­es have the third ver­sion num­ber equal to 0 (zero). Con­tin­u­ous Deliv­ery ver­sion num­bers and in non-zero num­bers. For exam­ple, IBM MQ 9.0.0 is an LTS ver­sion; 9.0.1 is the first CD ver­sion for IBM MQ 9.0.

Con­tin­u­ous Deliv­ery ver­sions always con­tain the lat­est fea­tures and bug fix­es; LTS releas­es are only updat­ed via fix packs and indi­vid­ual bug fix­es and include no new fea­tures; the only way to update a CD release is to install the new one over the installed version.