Gatling Frontline incrementConcurrentUsers query - do aws auto-scaling testing on Microservice - gatling

I will appreciate your advice here:
I am using Gatling as a performance tool.
I need to test (on AWS account) Microservice including auto-scaling configuration
in that case, I try to do something like that:
scn.inject(
incrementConcurrentUsers(20)
.times(120)
.eachLevelLasting(150 seconds)
.separatedByRampsLasting(50 seconds)
.startingFrom(20)
)andThen(scn.inject(constantUsersPerSec(300).during(30 minutes)))
by running the first setup i am getting good resoult and it will see like that:
BUT when this line added andThen(scn.inject(constantUsersPerSec(300).during(30 minutes))
my result will be looking like that:
but it did not work for me.
my goal is to Incremental the load for a few hours to validate the service scaling and after that you continue with the max load till the end of the test.
thanks

The thing is you try to concat different load models.
incrementConcurrentUsers - closed model.
constantUsersPerSec - open model.
You need to understand which model preferred for your application and use cases, etc.
There is good artical about models - https://gatling.io/2018/10/gatling-3-closed-workload-model-support/
Now return to load profile - recording the documentation andThen is used for chain chain scenarios. But in your case it's more about only the one scenario. Therefore I recommend use only one injector. You can unite metadsl and simple step like this:
setUp(
scn.inject(
incrementUsersPerSec(10)
.times(5)
.eachLevelLasting(3 minute)
.separatedByRampsLasting(1 minute)
.startingFrom(20),
constantUsersPerSec(75) during (40 minutes)
).protocols(protocol)
)

Related

Any examples of using a Wandsearcher in vespa ? (After a weighted set query)

Currently i am using the REST interface to query vespa, which seems to work great but something tells me that i should be using searchers in the application to make the client(server side code) a bit lighter (bundle the jar file in the application package) to make it a bit smoother. I have managed to do some simple searcher/processor applications. But this is a bit overwhelming.
So are there any readily available examples ?
Basicially i want to:
Send to /search?query=someId
Do a ordinary search for the weighted set on this documentID (I guess this one can be handy: https://docs.vespa.ai/documentation/reference/inspecting-structured-data.html)
Take those items in the response and add it to a wand item(s) and query for a wand with wandsearcher on a given field. Similar to the yql:
"select * from sources * where wand(interest, some weightedsets));","ranking":"combined_score" and return the matches.
Just curious also, apart from the trouble of string building with the http request i am doing at the moment are there any performance gains of using a searcher or go the java route vs rest?
thanks for any insight or code help i can start with.
There is an example of using the WandItem (YQL wand)here https://docs.vespa.ai/documentation/advanced-ranking.html and see also https://docs.vespa.ai/documentation/using-wand-with-vespa.html as there are two wand implementations available in Vespa, it sounds from the description that the wand() is what you want to use for this use case. For the first call you probably want to have a dedicated document summary to reduce the amount of data fetched for your first query and also the option of serving it out of memory only (See https://docs.vespa.ai/documentation/document-summaries.html)
Also see https://docs.vespa.ai/documentation/searcher-development.html as a general resource on writing searchers.
For your use case it makes a lot of sense to write a searcher to perform these two queries as your second query depends on the first and you avoid the cost of rendering/http/yql parsing which might matter if your client is remote with high network latency.

Custom Searcher - Blending of hits from different sources

We have a need for "Blending of hits from different sources", as per your documentation it is recommended to write a custom-searcher in JAVA. Is there a demo of this written somewhere on Github ? I wouldn't even know where to start :( I understand I can create search "chains" , preferably Asynchronous, and then blend results in JAVA before returning them...but then how would I handle paginations, limits...etc ? This all seems very complicated, for someone who doesn't even know JAVA that much. So, I am hoping someone has already written a demo for this ? Please ? Anyone ?
Thank you so much
EDIT to make my quesion clearer:
We are writing a search engine that fetches data from various websites. Some websites have 10mil indexable items, other websites only 100,000. When we present the results to end user, we want to include results from all our sources ( when match applies ). Let's say 10 results from each of the websites we crawl, so that they all get equal amount of attention on page. If we don't do custom blending, what happens is that the largest website with most items wins all our traffic.
I understand that we can send 10 separate queries to VESPA, and blend the results in our front end, but that seems very inefficient. Thus, the quesion of "Custome Searcher". Thank you so much !
That documentation covers some very advanced use cases which you do not have. Are your sources different Vespa schemas or content clusters? If so Vespa will by default blend the hits returned from each according to their relevance scores so there's nothing you need to do.
The two other most common use-cases are:
Some (or all) the data sources are external, so you need to write a Searcher component to fetch the external data and turn it into a Result.
You want the data to be blended in some custom way (rather than by relevance score). If so you need to exclude the default blending Searcher (com.yahoo.prelude.searcher.BlendingSearcher) and write your own.
If you provide some more information about your use cases I can give you some code examples.
EDIT: Use grouping to solve the need explained under "EDIT" in the question:
Create a "siteid" field when feeding (e.g in document processing).
Use the grouping expression all(group(siteid) each(max(10) output(summary())))
See http://docs.vespa.ai/documentation/grouping.html

Gatling Throttle holdfor not working

New to Gatling world but an experienced Loadrunner user.
I created a sample simulation to run two scenarios, each with 10 users and want to run it for 10 minutes. Below is what I have in my setUp function. But each time I run the simulation, it only runs for 136 seconds. The holdFor doesn't seem to take into effect.
setUp(
scn.inject(rampUsers(10) over (10 seconds)),
scen.inject(rampUsers(10) over (10 seconds))
)
.protocols(httpProtocol)
.throttle(
reachRps(2) in (10 seconds),
holdFor(10 minutes)
)
I am using Gatling 2.2.2 bundle.
Output: Simulation computerdatabase.BasicSimulation completed in 136 seconds
The throttle works as a bottleneck, effectively working as an upper boundary for how many requests will be sent. If your scenarios + injection profiles aren't able to generate as many requests as you would like in the first place, the ones that are generated simply pass through the throttle unhindered. The throttle cannot increase the load to match the desired RPS, it can only decreases it.
You will need to inject enough users into your scenarios for them to be able to generate the 2 RPS you want in the first place, and keep adding more of them over the course of the simulation, in order for the throttle to do what you are looking for.
Try changing your injection profiles to for example something like this (and adjust the constantUsersPerSec value as needed), I believe this might give you a load-profile a step closer to what you are looking for:
scn.inject(constantUsersPerSec(1) during(10 minutes))),
scen.inject(constantUsersPerSec(1) during (10 minutes)))
The example above was just a very quick and dirty way to illustrate the point of having to inject users over time, but as chance would have it, injecting 600 users in total over 10 minutes into a scenario is 10 users every ten seconds and should be exactly what you want, unless I'm falling ass first into a basic arithmetic error and/or misunderstanding.
It will also naturally ramp up and down to some extent, although you can more explicitly control the ramp up by chaining injection steps if you need, for example like this:
scn.inject(
rampUsers(10) over (1 minute),
constantUsersPerSecond(1) during (10 minutes)
)
For another approach to more explicitly control the ramp over time, you could also play around with a configuration like this:
scn.inject(
splitUsers(600) into(rampUsers(10) over(10 seconds)) separatedBy(10 seconds)
)

What is the best way (Least Read Operations) to do autocomplete on Google App Engine Using Objectify

I am currently using ajax to do autocomplete emails and would like to find out what is the best way to do this without too much read operations. Thanks!
The best way to do these kind of operations is use the following approach
Use full text search:
https://cloud.google.com/appengine/docs/java/search/
When creating a document to search on, you could tokenize the email id. for example if you have foobar#baz.com. you could tokenize it to f, fo, foo, foobar .... and save it into a textfield.
then use index.search to query for the results.
then every successful lookup can be cached for say 2 hours ( you can change it as per your requirement ).
Anytime you update the model add/update/remove entries then delete the memcache entries/flush the memcache, preferably using the datastore callbacks.
https://cloud.google.com/appengine/docs/java/datastore/callbacks
please note that the tokenize + adding a document could to be processed in task queue to fit into the "gae way of doing things"
Also as a footnote, you could try implementing client side caching mechanism using http cache control + etags. I have not implemented such a solution so others could pitch in how their experience was implementing such a solution.
https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching?hl=en

Updating Model Schema in Google App Engine?

Google is proposing changing one entry at a time to the default values ....
http://code.google.com/appengine/articles/update_schema.html
I have a model with a million rows and doing this with a web browser will take me ages. Another option is to run this using task queues but this will cost me a lot of cpu time
any easy way to do this?
Because the datastore is schema-less, you do literally have to add or remove properties on each instance of the Model. Using Task Queues should use the exact same amount of CPU as doing it any other way, so go with that.
Before you go through all of that work, make sure that you really need to do it. As noted in the article that you link to, it is not the case that all entities of a particular model need to have the same set of properties. Why not change your Model class to check for the existence of new or removed properties and update the entity whenever you happen to be writing to it anyhow.
Instead of what the docs suggest, I would suggest to use low level GAE API to migrate.
The following code will migrate all the items of type DbMyModel:
new_attribute will be added if does not exits.
old_attribute will be deleted if exists.
changed_attribute will be converted from boolean to string (True to Priority 1, False to Priority 3)
Please note that query.Run returns iterator returning Entity objects. Entity objects behave simply like dicts:
from google.appengine.api.datastore import Query, Put
query = Query("DbMyModel")
for item in query.Run():
if not 'new_attribute' in item:
item['attribute'] = some_value
if 'old_attribute' in item:
del item['old_attribute']
if ['changed_attribute'] is True:
item['changed_attribute'] = 'Priority 1'
elif ['changed_attribute'] is False:
item['changed_attribute'] = 'Priority 3'
#and so on...
#Put the item to the db:
Put(item)
In case you need to select only some records, see the google.appengine.api.datastore module's source code for extensive documentation and examples how to create filtered query.
Using this approach it is simpler to remove/add properties and avoid issues when you have already updated your application model than in GAE's suggested approach.
For example, now-required fields might not exist (yet) causing errors while migrating. And deleting fields does not work for static properties.
This doesn't help OP but may help googlers with a tiny app: I did what Alex suggested, but simpler. Obviously this isn't appropriate for production apps.
deploy App Engine Console
write code right inside the web interpreter against your live datastore
like so:
from models import BlogPost
for item in BlogPost.all():
item.attr="defaultvalue"
item.put()

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