JMeter cache and cookie manager give warnings

0
votes

I have a strange problem in 2.6 jmeter. I have a really simple test plan with couple of http samplers with cache and cookie managers on the thread level. Whenever "Use concurrent pool" is enabled for http samplers, I see the following warnings in the log:

jmeter.protocol.http.sampler.HTTPSamplerBase: Existing CacheManager HTTP Cache Manager superseded by HTTP Cache Manager jmeter.protocol.http.sampler.HTTPSamplerBase: Existing CookieManager HTTP Cookie Manager superseded by HTTP Cookie Manager

This repeats a huge number of times for each thread and may hang jmeter. But if the "Use concurrent pool" setting is disabled then everything is fine. There are no additional cookie or cache managers on the sampler level. I can not do without Cookie manager's functionality in my test plan.

My test plan looks like this:
Test plan
---Thread Group
------Cookie Manager
------Cache Manager
------Response assertion
------HTTP sampler
--------Header Manager
------HTTP sampler
--------Header Manager
------Aggregate report

2
cachingcookiesjmeterwarnings
How many cookie managers do you have and where are they placed? You probably only need or want one per thread group. – Oliver Lloyd
2 Things: 1. Checking Use Concurrent Pool should have no impact on this message. And 2. The volume of these calls will not hang JMeter, it will only write this message once per invocation in each iteration, you will hit another problem long before this becomes a bottleneck. Maybe you are just trying to run an unreasonable load from a single machine? Maybe try less listeners. – Oliver Lloyd
I use distributed env., each server do not exceed 300 threads (actually I have 50 threads x 4 concurrent connections per thread) which is (or was at least) the recommended limit + I'm monitoring jmeter with VisualVM which gives a clear view of the performance of each instance. You are wrong saying it will write this message once per thread, tried it with one thread and there were definitely more than 50 of them. And sorry if I was somewhat unclear but I use only one cookie manager and only one cache manager in the whole test plan, so logically there is no way a conflict could occur. – user716595
Right, but you do realise that "once per invocation per iteration" != "once per thread"? Anyway, maybe if your testplan is simple you could edit your question to outline exactly what you have - use the same ---- structure given in the answer below to indicate position. – Oliver Lloyd
I've added the test plan to the question. If I remove cache & cookie managers and enable concurrent connections in http samplers then no warnings, If I disable concurrent connections and keep the managers then everything's fine as well – user716595

2 Answers

2
votes

You have multiple Cookie and Cache managers in scope and this is causing this warning to appear. To remove the warning you should remove the additional, extraneous managers.

Eg.

Test Plan
---Thread Group
---HTTP Cookie Manager
-------Sampler
HTTP Cookie Manager

The above setup will cause this warning as both managers will be in scope for the sampler.

This:

Test Plan
---Thread Group
---HTTP Cookie Manager
-------Sampler

Will not cause the warning but will still produce the same results.

1
votes

I found that when had a "HTTP Request defaults" config element setup with "use concurrent pool" enabled I always got these warnings. Disabling that setting cleared up warnings, doesn't explain the why? however.