In client-side script 1st user creates events in a calendar for 2nd user, 2nd user accepts/declines them.
I would like to exclude possible errors during event creation and check if event request was created before 2nd user tries to accept it using xpath built on event request template like:
EventRequest_SubjectN
(N is iteration number of event request in a cycle, so if event request N wasn't created by 1st user, 2nd user action with event N fails).
Between these actions are another actions of both users, by this reason I can't use ${JMeterThread.last_sample_ok}.
Is there any analog of this function, but for necessary/specific action several steps ago, not for last sample?
What is the best way to organize IF-condition is that case?
I think about to add BeanShell PostProcessor after 1st user Event request N with a code like:
var rc = prev.getResponseCode();
if(rc.equals("200")){
vars.put('EventRequest_Subject_${N}', 'EventRequest_Subject_${N}');
}
and use not null condition for EventRequest_Subject_${N} in IF-controller for 2nd user.
But it doesn't work in this way. Where am I wrong?
UPD. Solution:
Tried 3 ways:
if Event_RequestN created - put into variable specific value, then use it in IF-condition before 2nd user action with Event_RequestN;
add action with specific assertion before 2nd user action with Event_RequestN and use ${JMeterThread.last_sample_ok} in IF-condition;
add action with xpath extractor before 2nd user action with Event_RequestN and use ${_isVarDefined(EventRequest_Subject${N}_FOUND)} in IF-condition;
and ended up with 3rd variant as the best on practice.
Don't use Beanshell, since JMeter 3.1 you're supposed to be using JSR223 Test Elements and Groovy language for scripting
Don't inline JMeter Functions or Variables into scripts, go for code-based equivalents instead
As per JMeter Documentation
Properties are not the same as variables. Variables are local to a thread; properties are common to all threads
so if you want to share a piece of data between 2 threads (virtual users) you need to use props, not vars
It's easier to implement your scenario using Inter-Thread Communication Plugin
Related
I am trying to implement an Event Sourcing system using Kafka and have run into the following issue. During a new user sign-up I want to check if the username the user provided is already taken. However, consider the case where 2 users are trying to sign-up at the same time providing the same username.
In my understanding of how ES works the controller that processes the sign-up request will check if the request is valid, it will then send a new event (e.g. NewUser) to Kafka, and finally that event will be picked up by another controller which will persist it in a materialized view (e.g. Postgres DB). The problem is that the validation of the request is done against the materialized view but the actual persistence to it happens later. So because the 2 requests are being processed in parallel (by different service instances) they might both pass the validation, resulting in 2 NewUser messages. However, when the second controller tries to persist those 2 NewUser messages in the database saving the second event will fail because of the violation of the uniqueness constraint for the username.
Any ideas on how to address this?
Thanks.
UPDATE:
In particular, I would like to verify whether the following are accepted approaches to the problem:
use the username as the userId (restrictive)
send an event to a topic partitioned by username and when validation
is done send an event to another topic
Initial validation against the materialized view won't be enough in most scenarios where you have constraints. There can always be some relevant events haven't been materialized yet. There are two main concurrency control approaches to ensure that correct results are generated:
1. Pessimistic approach:
If you want to validate constraints before you publish an event, you need to lock relevant resources (entity, aggregate or data set). The locking means your services must not be able to publish events on these resources. After this point, to get the current state of your data:
You can wait until all events published before locking are materialized.
You can read current state from the database and apply events on it in a separate process.
2. Optimistic approach:
In this approach, you perform your validations after publishing events. To achieve this, you need to implement a feedback mechanism. The process which consumes events and performs validations should be able to publish validation results. You can perform the validations in-memory when possible. Otherwise, you can rely on your materialized data store.
Martin Kleppman talks about a two-step solution for exactly the same problem here and in his book. In this solution, there are two topics: "claims" and "registrations". First, you publish a claim to take the username, then try to write it to the database, and finally publish the result to the registrations topic. At conceptual level, it follows the same steps in the second approach you have mentioned. In validation step, it avoids implementing validation logic and keeping secondary indexes in memory by relying on the database.
During a new user sign-up I want to check if the username the user provided is already taken.
You may want to review Greg Young's essay on Set Validation.
In my understanding of how ES works the controller that processes the sign-up request will check if the request is valid, it will then send a new event (e.g. NewUser) to Kafka, and finally that event will be picked up by another controller which will persist it in a materialized view (e.g. Postgres DB).
That's a little bit different from the usual arrangement. (You may also want to review Greg's talk on polyglot data.)
Suppose we begin with two writers; that's fine, but if there is going to be a single point of truth, then you are going to need synchronization somewhere.
The usual arrangement is to use a form of optimistic concurrency; when processing a request, you reserve a copy of your original state, then you do your calculation, and finally you send the book of record a `replace(originalState,newState)'.
So at this point, we have two writes racing toward the book of record
replace(red,green)
replace(red,blue)
At the book of record, the writes are processed in series.
[...,replace(red,blue)...,replace(red,green)]
So when the book of record processes replace(red,blue), it performs a check that yes, the state is currently red, and swaps in blue. Later, when the book of record tries to process replace(red,green), the book of record performs the check, which fails because the state is no longer red.
So one of the writes has succeeded, and the other fails; the latter can propagate the failure outwards, or retry, or..., precisely what depends on the specific mechanics in question. A retry should mean, of course, reload the "original state", at which point the model would discover that some previous edit already claimed the username.
Any ideas on how to address this?
Single writer per stream makes the rest of the problem pretty simple, by eliminating the ambiguity introduced by having multiple in memory copies of the model.
Multiple writers using a synchronous write to the durable store is probably the most common design. It requires an event store that understands the idea of writing to a specific location in a stream -- aka "expected version".
You can perform an asynchronous write, and then start doing other work until you get an acknowledgement that the write succeeded (or not, or until you time out, or)....
There's no magic -- if you want uniqueness (or any other sort of invariant enforcement, for that matter), then everybody needs to agree on a single authority, and anybody else who wants to propose a change won't know if it has been accepted without getting word back from the authority, and needs to be prepared for a rejected proposal.
(Note: this shouldn't be a surprise -- if you were using a traditional design with current state stored in a RDBMS, then your authority would be a user table in the database, with a uniqueness constraint on the username column, and the race would be between the two insert statements trying to finish their transaction first....)
I have a task where I need to perform two tasks based on the previous Sampler result.
If Assertion fails
{
send email with the error message.
}else
{
perform the tasks in while controller.
}
I have achieved the first part easily by providing the condition in If controller ${JMeterThread.last_sample_ok} == false
I have problems going to else block. I have tried two IF controllers but with no success.
Case here is need to perform one task only either IF block or Else block. But In my case it goes to both the blocks and perform both the tasks.
Can anyone help how to achieve this?
There is no "Else" block in JMeter, you have only "If" therefore if you need "Else" behavior you need to use 2 IF Controllers with opposite conditions.
But, for 2nd If Controller you won't be able to use this as this ${JMeterThread.last_sample_ok} variable will be overwritten with the result of your SMTP Sampler so if your SMTP Sampler will be successful ${JMeterThread.last_sample_ok} variable will become true therefore second If Controller will be executed as well.
So I would recommend the following approach:
If your Assertion Fails
In Beanshell PreProcessor define a custom variable like:
vars.put("run_while_controller", "false");
Put your While Controller under another If Controller and use ${run_while_controller} as a condition
Alternative option is stopping the test after sending an email, this can be done using i.e. Test Action sampler
Going forward I would suggest using Debug Sampler and View Results Tree Listener to double check all the JMeter Variables values, this is most convenient way to see all JMeter variables and properties values. See How to Debug your Apache JMeter Script article for more information on getting to the bottom of your JMeter test unexpected behavior.
We have a very weird issue in our Siebel 7.8 application.
In the Application_Start event we define a bunch of profile attributes, which determine if the logged user will be allowed to perform certain operations or not. The code is something like this:
if (userHasSuperpowers) {
TheApplication().SetProfileAttr("CanFly", "Y");
} else {
// CanFly is not set, and GetProfileAttr("CanFly") returns ''
}
Everything works fine, except for one of these profile attributes. The conditions are not met, so we don't set its value. But when we check it using GetProfileAttr... it returns 'Y' instead of ''.
I've checked the code. A lot. I've put traces everywhere, and I'm 100% sure that when the last line of the Application_Start event executes, the attribute is still empty. However, in the first Applet_Load event after the login (in the HLS Salutation Applet (HLS Home) applet), its value has already changed to 'Y'. Why!!? I've looked everywhere, but I can't find anywhere else where we'd be doing a SetProfileAttr. So far, I've ruled out:
Every browser and server script for all our applets, application, BCs and business services.
All the runtime business services (the ones defined directly in the application instead of the SRF).
The Personalization Profile business component fields.
SmartScripts (not that they would matter in this particular scenario, I just mention them to acknowledge that you can set profile attributes there too).
Workflows: every step invoking the SIS OM PMT Service method Set Profile Attribute.
Siebel magically setting its value. The profile attribute name is custom made, in Spanish, and it contains our project name and a row_id. I really don't think Siebel is using the same name for its own profile attributes :).
But wait, there is more, I left the best part for last: the problem only happens in our development environment!
It's not an SRF issue: if we promote the same SRF to our testing or production environments, it works and returns the expected value.
It's not a data problem: still with the same SRF, I can use my local thick client, connecting to our development database with the same login and password, and it works fine too.
It's not a concurrency problem: we are testing with only one user logged in. And even if we had more, they wouldn't share sessions. And even if they did, the value wouldn't be always 'Y'.
It's not a temporary glitch, or something due to a wrong incremental compilation or a corrupted SRF: we have been experiencing this for at least 6 months (obviously, in that time frame, we've had dozens of different SRF files... all of them having the same problem, but only in development, and only if you use the server and not the dedicated client... seriously...).
Where else could I search the profile attribute being set? I've read that they can be persisted to the DB, but in order to do so, you have to define them as a field in a BC based on an S_PARTY extension table, right?
Is there any way to trace profile attribute changes somehow? Maybe rising some loglevel?
How can I find out at least what's being executed after the Application_Start, before loading the first applet?
Any other ideas? I tried checking the SQL spool file too, but didn't find anything suspicious there either (i.e., any of the queries we use to check the conditions, being run twice with different parameters).
Update: following Ranjith R's suggestions, I've also checked:
Other vanilla business services which could be also invoked from a workflow to set a profile attr: User Registration > SetProfileAttr, SessionAccessService > SetProfileAttr and ISS Promotion Agreement Manager > SetProfileAttributes.
Runtime events setting profile attributes directly or using a business service (we don't have any runtime events apart from the vanilla ones).
Business services being called from DVMs (we only have vanilla data validation rules, and none of them apply to our buscomps).
Still no luck...
Ok... finally we found what's happening:
We access the URL to our server and get to the login page. This triggers a first Application_Start event, for the SADMIN user.
We set the profile attributes in that session. SADMIN is the Siebel administrator user, so yes, he hasSuperpowers and therefore we do TheApplication().SetProfileAttr("CanFly", "Y");.
The Application_Start event finishes.
We enter our username and password in the login screen to access into Siebel. This triggers a second Application_Start event, this time for our user. This is the one I was monitoring with the trace files.
We set the profile attributes again in the new session. Our user doesn't hasSuperpowers, so we don't set any value for the CanFly attribute.
The Application_Start event finishes, and CanFly is still empty.
Siebel merges both sessions into one before loading the first screen!! Or at least, it transfers over the profile attributes we had set for SADMIN.
I'm sure it happens that way, for two reasons. First, we changed the profile attribute name to include the username too. And second, instead of storing just an "Y", we are storing now the current date:
var time = (new Date()).getTime();
TheApplication().SetProfileAttr("CanFly_" + TheApplication().LoginName(), time);
We end up having CanFly_SADMIN, but no CanFly_USER, and the time value stored is the same we see in the log file for step 2... which is smaller than any of the values for the *_USER attributes.
So that's what happening. I still don't know why Siebel behaves this way, but that would be matter for another question. According to the Siebel bookshelf:
The Start event is called when the client starts and again when the user interface is first displayed.
...but it doesn't say anythign about it being called from two different sessions, different users too, and then merging them together. It must be something misconfigured in our dev environment, considering it doesn't happen in the other ones.
Does Siebel 7.8 have runtime Events? I can't recall. Runtime events have an action set for setevent, which can set/clear profile attributes.
There are still other vanilla business services which can set profile attributes, try searching in tools flat under business service methods for *rofile*tt*.
The SIS OM service can also be invoked from DVMs for from RunTime events directly, so thats also a possibility.
There is no logging system to see values of Profile Attributes changing, testing is the only way out.
I was wondering about the proper way to store state between sequence invocations in WSO2ESB. In other words, if I have a scheduled task that invokes sequence S, at the end of iteration 0 I want to store some String variable (lets' call it ID), and then I want to read this ID at the start (or in the middle) of iteration 1, and so on.
To be more precise, I want to get a list of new SMS messages from an existing service, Twilio to be exact. However, Twilio only lets me get messages for selected days, i.e. there's no way for me to say give me only new messages (since I last checked / newer than certain message ID). Therefore, I'd like to create a scheduled task that will query Twilio and pass only new messages via REST call to my service. In order to do this, my sequence needs to query Twilio and then go through the returned list of messages, and discard messages that were already reported in the previous invocation. Now, to do this I need to store some state between different task/sequence invocations, i.e. at the end of the sequence I need to store the ID of the newest message in the current batch. This ID can then be used in subsequent invocation to determine which messages were already reported in the previous invocation.
I could use DBLookup and DB Report mediators, but it seems like an overkill (using a database to store a single string) and not very performance friendly. On the other hand, as far as I can see Class mediators are instantiated as singletons, therefore I could create a custom Class mediator that would manage this state and filter the list of messages to be sent to my service. I am quite sure that this will work, but I was wondering if this is the way to go, or there might be a more elegant solution that I missed.
We can think of 3 options here.
Using DBLookup/Report as you've suggested
Using the Carbon registry to store the values (this again uses DBs in the back end)
Using a Custom mediator to hold the state and read/write it from/to properties
Out of these three, obviously the third one will deliver the best performance since everything will be in-memory. It's also quite simple to implement and sometime back I did something similar and wrote a blog post here.
But on the other hand, the first two options can keep the state even when the server crashes, if it's a concern for your use case.
Since esb 490 you can persist and read properties from registry using property mediator.
https://docs.wso2.com/display/ESB490/Property+Mediator
I have a SOAP UI 4.5.1, I have made a load test, it is working fine. My problem is that I run the same request every time and I need to change the values of the soap request I am sending.
For e.g. I have a block of my soap request:
<ns:Assessment>
<ns:Project>
<ns:ProviderId>SHL</ns:ProviderId>
<ns:ProjectId>SampleAssessment</ns:ProjectId>
</ns:Project>
</ns:Assessment>
Provider ID: SHL
Project ID: SampleAssessment
Is there a way to make those values changing from some kind of interval?
For e.g.: Provider IDs [SHL, SLH, LHS]
Project IDs [SampleAssessment, TestAssessment, AnotherAssessment]
And with a load test I am making three request so that for the first request values looks like this:
<ns:Assessment>
<ns:Project>
<ns:ProviderId>SHL</ns:ProviderId>
<ns:ProjectId>SampleAssessment</ns:ProjectId>
</ns:Project>
</ns:Assessment>
for the second like this:
<ns:Assessment>
<ns:Project>
<ns:ProviderId>SLH</ns:ProviderId>
<ns:ProjectId>TestAssessment</ns:ProjectId>
</ns:Project>
</ns:Assessment>
and so on...
Is there a way to make this happen with SOAP UI?
From my experience, you will need to use a Groovy Script step.
For example, if you have a step before your request that is a script, you can use something like:
context.setProperty("ProviderId", "SHL")
Then in your request, use:
<ns:ProviderId>${ProviderId}</ns:ProviderId>
Of course, this doesn't buy you much by itself. There are few ways to vary what the context.setProperty("ProviderId", "SHL") line will set. You can create a collection and iterate over it using something like:
def providers = ['ABC', 'DEF', 'GHI', 'JKL']
providers.each() {
context.setProperty("ProviderId", it)
testRunner.runTestStepByName( "nameofteststep" )
}
Where "nameofteststep" is the name of the Soap Request test step. This might sound odd, but if you right click the test step and disable it, the groovy script will still be able to execute it but it will not run sequentially. By that I mean that the groovy script will run it 4 times, but it won't run a fifth time when the script is complete because it is after the script. Then you just need to keep in mind that each load test thread makes four requests, but I am pretty sure that the SoapUI statistics will take this into account for you... might want to keep an eye out for it, though.
Alternatively, you could check the 'threadIndex' and set a the context variable based on that. A bit like this here: Log ThreadCount.
You could also use a collection without a loop and increment an index that you save as a testcase property and send the string corresponding to the index.
Personally, I think the first way is the most straightforward but I can provide an example of the other ones if you like.
There is a simple way of doing this without writing a groovy script.
After creating a test case you should include the below test steps:
1-Data source
2-Request
3-Loop
Data source will read an excel file (or other data source methods such as XML, groovy, JDBC, gird .. however the excel is the simplest one).
You should include the datas (that you need to change within the request)
Within the test request you need the right click and select "get data" . please notice that your test request should be as below
<ns:ProviderId>${ProviderId}</ns:ProviderId>
Then the last step is the "Loop" . This for returning to the first step until the data ends.
I hope this helps.