Hi all,

I have a situation where I am writing to global from different processes - let's call it an Event Queue.
There is then a different process that uses $order to read through the data - the PubSub processing BP.

Sometimes the writing of this global will form part of a transaction that also insert data into other tables, using tstart and tcommit.
If there is some issue, it will roll back, and the entry written to the global will also roll back.

0 6
0 107

Work Queue Manager (WQM) is a feature of InterSystems IRIS that enables you to improve performance by distributing work to multiple concurrent processes programmatically. The idea is that you split the work into chunks, and WQM distributes the chunks across worker processes and can provide the info that the work is done.

However, recently, I got an interesting question: there's a large logical transaction composed of ~1,000,000 individual objects and SQL inserts and updates. Some updates are CPU-intensive, so the original idea was to use WQM to split an update into chunks to speed things up.

But, here's a catch: if one of the individual 1,000,000 changes fails (there's a variety of application-level checks so that it can fail, and that's not even that abnormal a behavior), the entire transaction must be rolled back. That creates a problem: each chunk must report success before committing their individual transactions, and someone must get all these reports and decide if we are committing or not.

Unfortunately, it looks like WQM does not have a bidirectional communication between workers and manager, so I suggested an approach using events:

  1. Start jobs.
  2. Wait for all jobs to report success using $System.Event.WaitMsg().
  3. Send Commit or Rollback using the $System.Event.Signal().
2 9
1 198

Hi,

The system I am working on processes large numbers of records. Inserts, updates and so forth. There are multiple processes that can potentially work on the same table at the same time.

It is an almost impossible task to try and time these processes to not run at the same time, due to volumes, SLAs, etc.

Every now and then there are a few locking issues, Not many considering the volumes. It is just a bit of a nuisance as we need to reprocess these records later.

0 6
0 190
Article
· Oct 19, 2022 3m read
Ingestion and Querying Speed Test

The capacity of taking numerous records every second while also facilitating real-time queries simultaneously in real time is called Hybrid Transactional Analytical Processing (HTAP). It is also called Transactional analytics or Transanalytics or Translytics and is a very useful element in scenarios where there is constant flow of real time data coming from IIOT sensors or data on fluctuations in stock market, and supporting the need for querying these data sets in real-time or near real-time.

4 4
0 766

Hi All

When performing an update transaction on patient data in GUI Apex 5.8 cache2017, we randomly get a ‘Database Connection Lost’ error. Subsequently the application quits and the incomplete transaction is rolled back.

We have confined its not a network issue as we can still query the database using CHUI Apex when these events occur.

so any input appreciated.

0 1
0 271

will InterSystems fix the Transaction-Handling for the .Net Connection Provider?

Nor the Property IsTransactionAcvtive nor TransactionLevel is set on the Connection when using BeginTransaction.

Latest PreView will give me problem as InterSystems removed removed the TStart() Option to create the Transaction that way which gave back a TransactionObject whith working versions...

0 2
1 296
Question
· Jan 12, 2020
Timeout for $zf

In one of the projects, when we have ECP with 10 ECP application servers, from time to time we faced the issue when our journals fail to purge, due to open transactions. While we have about 100-150 GB journal files per day, it quite quickly became a big issue, and with mirroring a very big issue. Mostly we just rebooted our ECP Data server, so it searches rollbacks any transactions, but such process is too long, may steal a few hours. I did not find any way, how to get the list of the open transactions from one place from ECP Data Server. We just migrated our Data server to 2018.1.

3 4
0 855
Article
· Nov 11, 2019 11m read
Transactions in Global InterSystems IRIS

InterSystems IRIS supports a unique data structure, called globals, for information storage. Essentially, globals are persistent arrays with multi-level indices, having several extra capabilities—transactions, quick traversal of tree structures, and a programming language known as ObjectScript.

I'd note that for the remainder of the article, or at least the code samples, we'll assume you have familiarised yourself with the basics of globals:

6 7
1 855

Hello community!

I have a question about the %OnSave method of a class. We have a class that has two properties that are classes.

Class A

Class B

Class C

Class A.PropertyB as Class B

ClassA.PropertyC as Class C

Classes B and C also need to point back to Class A - it's just the way it is. We need to be able to use any one of these classes and get to the others (it's actually even more complicated than this, as Classes B and C also have a PropertyC and PropertyB as well, respectively) :

0 3
0 802
Article
· Jul 1, 2019 2m read
Transaction suspencion

It’s often useful to make changes inside the current transaction, that would not be rolled-back if transaction is rolled-back. For example to do some logging.

This can be achieved by using global that is mapped to temporary database -- IRISTEMP. All globals that start with ^IRIS.Temp* are mapped to IRISTEMP by default. Problem with such approach is that IRISTEMP is cleaned on InterSystems IRIS restart, so this log is lost.

What else you can do is -- suspend transaction temporarily, do the logging, and then resume the same transaction.

2 8
1 483

If I wanted to build a web-based dashboard that monitored various HIE transactions where would I start?

Examples of measures would be Provide & Registers by Facility, Patient Views by facility or even PHR related data.

I have a successful POC that uses nodejs, html and SQL but I think it makes more sense to use Intersystems technology all the way around, I just don't know where to begin.

0 10
0 571