Re: IBMi to AWS postgreSQL data warehouse

You really don't want to be talking to AWS from a trigger..

You're looking at 400ms response for HTTP and probably 800ms for HTTPS...

Assuming that you have to connect, send, disconnect for every request.
Which you would for anything but changes being made by a batch job.

Additionally, with HTTPS...if you happen to have lots of jobs connecting at
once, you can run into machine gate waits in the DCM.

They way I have done this is to have Db2i triggers write out to a data
queue. Then have a background job send the data to AWS.

The background job can keep the connection open and just keep sending as
long as there's another entry on the queue.

In my case, we can have multiple worker jobs pulling off the queue, but in
your case, you probably want just a single job to keep the transactions
ordered.

You might want to multiple queues for sets of tables, or even one queue per
table if there's enough changes.


Charles




On Thu, Oct 24, 2019 at 8:14 AM Jay Vaughn <jeffersonvaughn@xxxxxxxxx>
wrote:

vern - way too much fun.

so... i'm pretty well versed with what can be developed on the i, I just
need to educate myself more on "connection" options and best overall
platform to platform connection possibility?

Like...

my trigger i developed to bail out the symDS could be a pretty viable
option in this case, instead of pushing the before/after row to a local
symDS table on the i, why could'nt i just push that row directly to the AWS
cloud database?
Of course I have to keep in mind the ability to "re-sync" the two databases
at anytime and that would just be another mass insert cross platform.
I'm probably way oversimplifying this... but isn't it possible just to

- put triggers on the IBM i tables for (insert/update/delete) events and
have he trigger pgm connect to remote database (in this case AWS postGre
SQL)
- when needed to do a resync, simply run a process to mass distribute ever
row to target database?

tia

Jay

On Thu, Oct 24, 2019 at 9:32 AM Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx>
wrote:

Hi Jay

Too much fun, eh?

Products such as SEQUEL have the ability to export data by various
means, including FTP. They can also communicate with non-IBM i RDBMS
directly using JDBC.

You might look at generating things like XML or JSON - IBM i SQL has
several tools for that, and can be executed in RPG. There are also tools
like CGIDEV2 and Scott Klement's JSON tooling, if you want to roll your
own. I can even imagine writing an RPG-Open Access tool that could be
used to "WRITE" to the ETL using native RPG opcodes.

HTH
Vern

On 10/24/2019 7:15 AM, Jay Vaughn wrote:

So our non i folks decided to create a small 29 table DWH for a client.
They know little about our tables.
They used symetricDS to pull from the i and populate a staging

database.

An ETL tool then moves that to an AWS cloud PostgreSQL data warehouse.

The symDS tool auto generates sql triggers that are slapped on our i
tables. A couple of tables were so large in row size (many columns),

that

the auto generated sql triggers were so inefficient that I had to

replace

them with an i DB2 trigger that literally hands off the before/after

image

to a batch process to carry out the insert of those images to a symDS

table

that is also on the i. Apparently the symDS tool pulls changes form

that

symDS table on the i.
Then, due to the fact that we have initialized blanks in some of our

zoned

fields that sql doesn't play well with, I also had to put our own

trigger

on that one... and there may be more eventually.

I'm at the point where I'm convinced this is not the best game plan for

the

DWH.

Has anyone got any suggestions for a better IBMi to AWS postgreSQL
replication that would eliminate that symDS staging piece? Preferably
something that can connect directly to the AWS cloud from the i... even

if

custom code needs to be written?

tia

Jay

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