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Eduard Lebedyuk · Mar 12 go to post

I was confused a bit by the practice question 19 

check whether the caller correctly passed an instance of Sample.Person or a subclass.

I thought it meant:

check whether the caller correctly passed an instance of Sample.Person (which would be correct) or a subclass (which would be incorrect).

But it meant:

check whether the caller correctly passed an instance of Sample.Person or a subclass (both would be correct).

Eduard Lebedyuk · Mar 11 go to post

Use schedules or if you need just close enough you can do this:

  • Check how much time, on average BS takes to run. Let's say X seconds.
  • Set Call Interval on your BS to 86400-X.
  • Start BS at 10:00 AM.
  • Assuming the average runtime stays constant, it should work well enough.
Eduard Lebedyuk · Feb 18 go to post

This can possibly work if you make %Persistent a secondary superclass. In that case, new properties would go to a separate subscript, and your setup can maybe work (requires testing).

Storage works like this (parent has N properties, Child - X):

Child Extends %Persistent, Parent:

^a(id) = $lb("", prop1, prop2, ..., propX)

Child Extends Parent, %Persistent:
 

^a(id) = $lb("Child", propA, propB, ..., propN)
^a(id, "Child") = $lb(propO, propP, ..., propX)
Eduard Lebedyuk · Feb 17 go to post

I use return where it's important that we exit (middle of the loop, etc) immediately, in all other cases I use quit.

Eduard Lebedyuk · Feb 12 go to post

I think you might want to track these numbers instead:

  • Number of properties. $lb is list, so the larger the number of elements in a list the longer the time to get to the last element. Also larger larger lists exhaust the global buffer faster, so they might be less optimal. 
  • Method size in sloc. Ideally, your class shouldn't have methods spanning hundreds (thousands) of lines.

I wouldn't worry about total class length, but rather the number of individual elements and method sizes.

There's also class limits docs, but if you hit them, you probably have an issue already.

Eduard Lebedyuk · Feb 11 go to post

I'm thinking we may need to create a custom business operation extending the default one EnsLib.HL7.Operation.TCPOperation, and we would need to wrap up the RetryCount inside the response. What do you think?

I think you are correct. RetryCount is a runtime property, I don't think it's stored anywhere longterm, so you need a custom BO to save it. There are some workarounds you can attempt:

  • Query event log
  • Get current retry count using:  $$$GetJobMonitor(tConfigName,$$$SystemName_":"_$Job,$$$eMonitorRetry)

But I would definitely recommend subclassing.

Eduard Lebedyuk · Feb 9 go to post

Check ParseIOStream/ParseFramedIOStream from EnsLib.HL7.Parser. These methods take a stream (read to a specific position) and return next HL7 message. Overall loop can be seen in EnsLib.HL7.Service.FileService's OnProcessInput.

Eduard Lebedyuk · Jan 8 go to post

However, it is often difficult to test just the REST API without inadvertently involving the authentication scheme, the web application configuration, or even network connectivity. Those are a lot of hoops to jump through just to test the code within your dispatch class.

Another way you can do this is by splitting web (rest) api from the business logic. I think ideally your REST handler method does only the following two things:

  • Parses incoming request
  • Verifies incoming request (debatable, might also be offloaded to the underlying API)
  • Calls underlying API

This way you can focus on unit testing your underlying api layer and keep the REST parts of your implementation as simple as possible.

Eduard Lebedyuk · Jan 8 go to post

You can use BPs to do that automatically.

BS (pool size 1) sends file to BP (1 request, pool size 1).

BP parses the file and sends X async requests to BO (pool size >1) for processing, total request count is stored in BP.

BP OnError/OnResponse methods are called once rows are being processed, maintain count here.

Once OnError/OnResponse count matches original count send a final batch request.  

Eduard Lebedyuk · Dec 18, 2025 go to post

a-z, A-Z only. Everything else is considered non-alphabetic, although I guess non-latin characters would be a more correct term. 

Eduard Lebedyuk · Dec 17, 2025 go to post

PS: why is the correct result in the testNumbers method 321 and not 213?

Thanks for noticing! Fixed.

Eduard Lebedyuk · Dec 16, 2025 go to post

Check out %GetSetting implementation in Ens.Config.DefaultSettings:

// Look in table starting with most specific match
If $D(^Ens.Config.DefaultSettingsD(pProductionName,pItemName,pHostClassName,pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD("*",            pItemName,pHostClassName,pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD(pProductionName,"*",      pHostClassName,pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD("*",            "*",      pHostClassName,pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD(pProductionName,pItemName,"*",           pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD("*",            pItemName,"*",           pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD(pProductionName,"*",      "*",           pSettingName),data)
|| $D(^Ens.Config.DefaultSettingsD("*",            "*",      "*",           pSettingName),data)

In your case your first setting would be resolved on line three:

$D(^Ens.Config.DefaultSettingsD(pProductionName,"*",      pHostClassName,pSettingName),data)

And your second setting would be resolved on line five:

|| $D(^Ens.Config.DefaultSettingsD(pProductionName,pItemName,"*",           pSettingName),data)

But since line three resolves to a valid setting, line five would never be hit.

To work around that provide both item name and class name explicitly - it would be resolved on the first line for your outlier (since both item and class match) and the rest of the items would get their setting resolved on line three.

Eduard Lebedyuk · Dec 15, 2025 go to post

1️⃣ When you joined the Developer Community and how you first discovered it.

November 2015 not long after DC started. @Evgeny Shvarov told me about it.


2️⃣ A meaningful moment or story from your personal journey here.

I've been writing my Continuous Delivery series for seven years now! That's one of my longest writing projects.
3️⃣ An article, question, or discussion you consider especially valuable — one you believe others should take the time to revisit.

Lots of great stuff to find here on DC! 

This post by @Guillaume Rongier is probably the one I revisited the most over the years.

This post by @Dmitry Maslennikov too.

This comment by @Timothy Leavitt (wrote an article based on that). Also this one - should be in product imo.

Eduard Lebedyuk · Nov 3, 2025 go to post

Great article!

Highly recommend adding a common package root. I.e. not Operation.Alert but Company.Operation.Alert. 

This way querying %Dictionary/InformationSchema becomes much easier since you always know what to filter on.

Eduard Lebedyuk · Oct 29, 2025 go to post

It will work with any HTTP request verb.

Most REST dev clients have support for HTML preview, just remember to set Content Type. I don't think swagger-ui can do that as it's not an app, rather a page running in a browser.

Eduard Lebedyuk · Oct 28, 2025 go to post

Set response type to HTML:

ClassMethod Test()
{
	set %response.ContentType = "application/html"
	do ##class(%CSP.Utils).DisplayAllObjects()
	quit $$$OK
}

In Postman click Preview button:

Eduard Lebedyuk · Oct 9, 2025 go to post

URL must have a scheme (either TCP or SSL). I don't think your (redacted) URL has a scheme.

If that does not help, try to init the object directly to see what's going on:

Set client=##class(%Net.MQTT.Client).%New(Url, ClientID, QOS, KeepAlive, LWTTopic, LWTMessage)

When creating a new client instance at minimum the url to connect and a client id is required to be specified.
The client id must be a utf-8 string which is used to uniquely identify the client.
This takes the form "tcp://localhost:1883" where the scheme is tcp and the host and port are seperated by a colon. If
you are using ssl you should specify the url in the form "ssl://localhost:8883" where scheme is ssl.
The second parameter is a string which the broker can use to identify the client. The client will generate an id if not specified.
The third parameter defines the required quality of service, 'Fire and Forget' (0) or 'Wait for Delivery' (1).

The fourth parameter is the keepalive interval, defaults to 60. 
The client will send keepalive messages to the broker according to the specified interval. The final pair of parameters specifies the last will and testament topic and associated message.
The LWT (last will and testament) feature tells the broker to deliver the Last Will message to the Last Will topic, should the client unexpectedly disconnect.

Note, %New() can error so it's important to check that the return value with $IsObject() and examine the %objlasterror status value should the %New() not return a valid object.

Eduard Lebedyuk · Oct 9, 2025 go to post

Doubt it - $system.OBJ.MakeClassDeployed deletes the source code so there's nothing to recompile. Contact the WRC maybe they can suggest something, but without the source code there's not much anyone can do.

Maybe you still have this class in your source control?