topic Re: Interesting Behavior when using queryExecutionClient.queryExecute in Developer Q&A Forum

Interesting Behavior when using queryExecutionClient.queryExecute

DeeJay — Tue, 12 Dec 2023 23:16:28 GMT

I recently watched "A Practitioners Guide to "Dynatrace AppEngine: Everything thinkable is now possible" https://www.youtube.com/watch?v=D5SDmLx6Aj4. where Stefan Wassebauer did a technical demo of fetching dt.entity.service and getting the called and calling services. I thought I would replicate his work to cement my knowledge. Without the code and some of the DQL being off screen. I started with Notebooks in my environment to make sure I knew where to start.

This is the DQL that I ended up with:

fetch dt.entity.service

| fieldsAdd num_callers = arraySize(called_by[dt.entity.service]), num_called = arraySize(calls[dt.entity.service])
| filter num_callers > 1
| filter num_called > 1
| limit 20

when I added this to my code for app Engine

export default async function () {

const result = await queryExecutionClient.queryExecute({

body:{

query: "fetch dt.entity.service | fieldsAdd num_callers = arraySize(called_by[dt.entity.service]), num_called = arraySize(calls[dt.entity.service]) | filter num_callers > 1 | filter num_called > 1 | limit 10",

requestTimeoutMilliseconds: 30000,

},});

I found that I was only getting 1 record returned, after a little experimenting with different DQLs including some Logs, I found I needed to add a ", from:now() - 100d" into my DQL, I am only a couple of months into working with Dynatrace and DQL is still new to me but I don't understand why I would need a time range in my DQL when working with dt.entities. Can someone point me to the explanation of this? Code change to make it work

export default async function () {

const result = await queryExecutionClient.queryExecute({

body:{

query: "fetch dt.entity.service , from:now() - 100d | fieldsAdd num_callers = arraySize(called_by[dt.entity.service]), num_called = arraySize(calls[dt.entity.service]) | filter num_callers > 1 | filter num_called > 1 | limit 10",

requestTimeoutMilliseconds: 30000,

},});

Re: Interesting Behavior when using queryExecutionClient.queryExecute

gilgi — Wed, 13 Dec 2023 06:58:08 GMT

@DeeJay ,

Could it be that it's just because you don't have services with both number of callers and called services are greater than 1 in the whort time period?

I would suggest first display the values without increasing the timerange to make sure its correct.

Re: Interesting Behavior when using queryExecutionClient.queryExecute

DeeJay — Wed, 13 Dec 2023 13:58:50 GMT

@gilgi

Thanks for your comment, the issue I am having is caused by an assumption on my part. I was testing my DQL in Notebooks and I assumed the time range was the same as the default in my appEngine app. By default a new Notebook Query Grail on my system is Last 7 days, and clearly in the queryExecutionClient.queryExecute the time range is less.

The other assumption I was making is that a dt.entity.service didn't have a time range but when I did a
describe dt.entity.service in my notebook, I found the lifetime field which is a TIMEFRAME which makes sense now that I think about it.