Reading custom metrics from the last build for custom baseline comparisons - azure-devops

I'm planning to introduce linting into a rather massive code base. Fixing all existing issues beforehand is not possible, so seeing thousands of linter errors at start is inevitable.
I'd like to record the number of detected errors each time the build runs for master and treat this number as a success / failure threshold. If a new pull request does not exceed the current baseline, its pipeline passes and so the proposed change is good to go. However, if the number of errors increases, I'd like the pipeline to fail, thus preventing the merge.
This functionality I’ve described narrows down to writing variables to Azure DevOps servers as some side-effects of builds and also reading these values from the previous build. This looks very similar to comparing code coverage, however, I can't seem to find any docs on how to implement the read-write logic manually.
What pipeline task could I use? What else can I leverage to track a custom metric over a number of builds and compare the value with previous? To summarise, my ultimate goal is to gradually lower an arbitrary value from a large number to zero over the course of several months.

Related

Why is executionStartToCloseTimeoutSeconds required?

When using the Java client to start a workflow in Candece "executionStartToCloseTimeoutSeconds" is required on the Workflow. If I have a workflow that can run for an indeterminate amount of time, how do I get around this restriction?
That was a mistake to require this value. The new version of the platform I'm working on (temporal.io) defaults this value to infinity.
an indeterminate amount of time
First of all I believe indeterminate amount of time is not infinite amount of time.
As letting a workflow execution run and grow infinitely is anti-pattern in Cadence workflow. See Recommendation #5 in this article https://longquanzheng.github.io/cadence-lab/book/learnings/what-should-be-in-a-workflow-or-an-activity-in-cadence.html
A good timeout value can protect your workflow grow infinitely.
Because it's not recommended to let workflow run forever, as it will cause potential performance issue in both worker and server, the original idea is to enforce client providing a timeout value. We didn't provide defaults, as it's difficult to have a reasonable default for all use cases.
A too small default values will be even worse, because no one like workflow timeouted in production unexpectedly. Even though you can use "Reset" command to reopen it.
A too big default value, like Maxim suggests, is slightly better than too small values. But I personally disagree because that induces client forget thinking about how long the workflow will run, and how long the workflow history will grow. This will also turn out to be a production issue at some points later.
The biggest issue I see is that this required option is not friendly. It should be compiling error instead of running error. I think this is probably we can improve in Cadence -- if this is a required field, make it required at coding experience. At the same time provide some hardcoded fake "infinite" value to help some edge cases may also make sense.
Back to you question, I would suggest using some fake infinite value if you think it's indeterminate. An good example here is in Cadence system workflow: https://github.com/uber/cadence/blob/11547ee6db5dd306cb507b263381a6ea94c3faf1/service/worker/scanner/workflow.go#L48

Uber Cadence Workflow Version Change Compatibility

I understand that I cannot make backward incompatible changes to Workflows per:
How to make changes or fixes to Uber Cadence Workflow without breaking determinism?
However I am not sure what "backward incompatible" means here. Can I simply not deploy new code without using getVersion, period? Or as long as the history tracking that is used for restoration is compatible between the 2 versions then I can update without getVersion? Or I can update without getVersion under some under conditions?
Generally anything that can change the way the history is generated is considered backwards incompatible. The following changes are backwards compatible:
Any activity implementation.
Duration passed to sleep and timer creation function.
Changing arguments to activities.
Changing activity options and retry policies.
Changing values of variables that don't affect the workflow execution path. For example if some variable accumulates some data and this data is only used in a query.
We recommend saving a few histories and then replaying them as part of unit tests to find out about non compatible changes earlier.

How Can use real-time workflow in CRM 2015?

I have a real-time workflow for creating unique numbers. This workflow get a numeric field from my custom entity, increase it by 1, and update it for next use.
I want to run this workflow on multiple records.
Running on-demand mode, it works fine,and I have true and unique numbers, but for "Record is Created" mode, it dose not work fine and get repeated numbers.
What I have to do?
This approach wont work, when the workflow runs on demand its running multi-threaded, e.g. two users create two records, two instances of the workflow start. As there is no locking mechanism you end up with duplicated numbers.
I'm guessing this isn't happening when running on demand because you are running as a single user.
You will need to implement a custom auto number approach, such as Auto Number for DynamicsCRM.
Disclaimer: I work for Gap Consulting who produce the tool linked above.

Storing code metrics

I'd like to write a pre-commit hook that tells you if you've improved/worsened some code metric of a project (i.e. average function length). The hook would have to know what the previous average function length was and I don't know where to store that information. One option would be to store an additional .metrics file in the repo but that sounds clunky. Another option would be to git stash, compute the metrics, git stash pop, compute the metrics again and print the delta. I'm inclined to go with the latter. Are the any other solutions?
Disclaimer: I am author of the Metrix++ tool, which I am using in the workflow I described below. I guess the same workflow can be executed with other tools capable to compare the results.
One of the ideas you suggested works perfectly, if you add a couple of CI checks (see the steps below). I find it solid. Not sure why you are considering it clunky.
I have got a file with metrics results which is updated before each commit and stored in VCS. Let's name this file metrics.db, and consider automation of the following workflow on build/test of a project:
1) if metrics.db has not been changed since last checkout (i.e. it is the original data for the previous/base revision), copy it to metrics-prev.db
2) Collect metrics for current code, what produces metrics.db file again. Note: It is very helpful when a metrics tool can do iterative scans for the best performance (i.e. calculate metrics for updated functions/classes), so it gives you the opportunity to run metrics tool on every build, including iterative.
3) Compare metrics-prev.db with metrics.db. If metrics identify regressions, fail the build and [optionally] do not allow to commit - team rule. If metrics are good, build is successful, and commit may happen.
4) [optionally] you may run Continuous Integration (CI) which validates that the actual committed metrics.db file corresponds to the committed code for the same revision (i.e. do the same 1-3 steps and make sure that the diff is zero at the step 3). If diff is not zero, it means somebody forgot to update the metrics.db file, and presumably did not execute pre-commit check, so revert the change.
5) [optionally] CI may do steps 1-3 if you fetch metrics.db as metrics-prev.db from the previous revision. In this case, CI may also check that the collected metrics.db is the same as committed (alternative or addition for the step 4).
Another implementation I have seen: metrics.db files are stored in a separate drive, out of VCS, and custom script is able to locate corresponding metrics.db for a revision. I find this solution unreliable as the drive can disappear, files can be moved and renamed, and so on. So, placing the file in VCS is better solution, but any will work.
I have attempted to do the alternative you suggested: switch to the previous revision and run the metrics tool twice. I abandoned this approach for several reasons: metrics check script alters your source files (so, it is impossible to include it into iterative rebuild and continue to work smoothly with your IDE as it will complain about changed files), and secondly it is very slow performance (comparing with iterative re-scans, it is extremely slow).
Hope it helps.

Scheduling variables sized work items efficiently

(I have also posted this question at math.stackexchange.com because I'm not sure where it should belong.)
I have a system with the following inputs:
Set of work items to be completed. These are variable sized. They do not have to be completed in any particular order.
Historical data as to how long work items have taken to complete in the past. However, past performance is no guarantee of future success! That is, once we come to actually execute a work item, we may find that it takes longer or shorter than it has previously.
There can be work items that I have never seen before and hence have no historical data about.
Work items further have a "classification" of "parallel" or "serial".
Set of "agents" which are capable of picking up a work item and working on it. The number of agents is fixed and known in advance. An agent can only work on one work item at a time.
Set of "servers" against which the agents execute work items. Servers have different capabilities. Specifically, they are capable of handling different numbers of agents simultaneously.
Rules:
If a server is being using to execute a "serial" work item, it cannot simultaneously be used to execute any other work item.
Provided a server isn't being used to execute any "serial" work items, it can simultaneously handle as many agents as it is capable of, all executing "parallel" work items.
There are a handful of work items which must be executed against a specific server (although any agent can do that). These work items are "parallel", if that matters. (It may be easier to ignore this rule for now!)
Requirement:
Given the inputs and rules above, I need to execute the set of work items "as quickly as possible". Since we cannot know how long a work item will take until it is complete, we cannot possibly hope to derive a perfect solution up front (I suppose), so "as quickly as possible" means not manifestly doing something stupid like just using one agent to execute each work item one by one!
Historically, I've had a very simple round-robin algorithm and simply sorted the work items by descending historical duration such that the longest running work items get scheduled sooner and, hopefully, at the end of the cycle I'm able to keep all agents and servers reasonably well loaded with short-duration work items. This has resulted in a pretty good "square" shape to the utilization graph with no long tail of long-duration work items hanging around at the end of the cycle.
This historical algorithm, however, has required me to pre-configure the number of agents and servers and pre-allocate work items to "pools" and assign pools to servers, and lots of other horrible stuff. I now need to support a dynamic number of agents and servers without having to reconfigure things. (Note that the number of servers will be fixed during a cycle - that is, the number will only change between cycles - but the number of agents may increase or decrease in the middle of the cycle.)
Once all work items are complete, we record how long each work item took to feed in to the next cycle and start again from the beginning!