fix(limit-conn): always save the data of the limit object, and release it in log phase.

[membphis]

What this PR does / why we need it:

fix #2450

Pre-submission checklist:

• Did you explain what problem does this PR solve? Or what new features have been added?
• Have you added corresponding test cases?
• Have you modified the corresponding document?
• Is this PR backward compatible?

[membphis]

@LY-GO you can make a try with this PR

[LY-GO]

@LY-GO you can make a try with this PR
two question:
1.now i have a requirement.iI need to add a key that it belonds to config of limit-conn-plugin .I just modify the define of key?

2.i modify the code of limit-conn according to your repair.But the response code is 500

[LY-GO]

@LY-GO you can make a try with this PR
2.i modify the code of limit-conn according to your repair.But the response code is 500

[spacewander]

@LY-GO
I think the 500 may be related with #2472

[LY-GO]

@LY-GO you can make a try with this PR
2.i modify the code of limit-conn according to your repair.But the response code is 500

@LY-GO you can make a try with this PR

I test the plugin,i find it don't work;now every request can success,even if number of request over concurrency limit.I just copy your code,overwrite a new plugin and reload the plugin

[LY-GO]

@LY-GO you can make a try with this PR
2.i modify the code of limit-conn according to your repair.But the response code is 500

@LY-GO you can make a try with this PR

I test the plugin,i find it don't work;now every request can success,even if number of request over concurrency limit.I just copy your code,overwrite a new plugin and reload the plugin

two suggesstions:
1.When you use limit-conn plugin,you must set default_conn_delay > 0, otherwise you will find assertion failed.
2.When you test limit-conn plugin,your upstream must set sleep time.Because concurrency is required at the same time .

[spacewander]

@LY-GO

I test the plugin,i find it don't work;now every request can success,even if number of request over concurrency limit.I just copy your code,overwrite a new plugin and reload the plugin

2.When you test limit-conn plugin,your upstream must set sleep time.Because concurrency is required at the same time .

Is the note 2 caused the plugin didn't work in your test? Does it work after you set sleep time?

[membphis]

@LY-GO please provide your plugin configuration. it maybe invalid.

[LY-GO]

@LY-GO

I test the plugin,i find it don't work;now every request can success,even if number of request over concurrency limit.I just copy your code,overwrite a new plugin and reload the plugin

2.When you test limit-conn plugin,your upstream must set sleep time.Because concurrency is required at the same time .

Is the note 2 caused the plugin didn't work in your test? Does it work after you set sleep time?

When you set sleep time in your procedure,you can use jmeter to test plugin and the plugin can work successfully.

[spacewander]

I think the problem is solved. What made the fix won't work is just the way of test (for example, the upstream doesn't hold the connection).

[LY-GO]

I think the problem is solved. What made the fix won't work is just the way of test (for example, the upstream doesn't hold the connection).

I don't understand word "the upstream doesn't hold the connection"

[membphis]

@tokers @moonming @spacewander I have fixed the conflict, you can take a look

[moonming]

why modify this test case？

[membphis]

old test cases have space at the end of line.

my editor helps me do the slim, this is fine.

[moonming]

Shouldn't the request be rejected here? I did not understand

[membphis]

All requests are sent one after another, they are not concurrent.

So the request should never be limited for "conn": 1,.

In the old code, it will be limited due to this bug.

[membphis]

@moonming @tokers @nic-chen please take a look at this PR