Bukkit

@LordKainzo

Just like "/testncp velocity 3" for instance. It will add velocity for the looking direction.

@LordKainzo

Thanks, that is what i am looking for.

Does "/testncp velocity ..." work ?

@LordKainzo

Setting one of the debug flags would do it:

checks:
  debug: true
  # ....
  moving:
    debug: true
    # ...

The interesting part is from jumpphase=0 with ground -> ground or ground -> air, all the way to the violation.

TestNCP:
http://dev.bukkit.org/server-mods/ncptools/files/4-test-ncp-1-3-0/

Also interesting for comparison would be if you get violations for "/testncp velocity ..." putting in the amount, it would add velocit into the viewing direction.

Edit: What server version are you testing with ?

@LordKainzo

With graceticks 100, something is wrong :), it means that velocity can't get invalidated within 100 ticks usually, i.e. 5 seconds. The test setup is a local server or a remote server?

Is it the latest TestNCP version (showing lag too)?

Concerning the moving debug trace: can you paste the move-spam from jumphase 0 until violation? (it should be something like hannebal XYZWorld ....(coordinates)... and other.

Setting moving.debug or checks.debug to true should result in such a trace.

To add: the debug trace is best done with no other / few people on the same server.

A new release is available:
NoCheatPlus 3.8.10-RC-b438

A couple of new checks, a good range of fixes. Some checks have been "revived", since they had been removed previously or even been mostly inoperable (e.g. direction checks).

@Sotlol1

I recommend not to use it.

Edit: It may work without plugins or with "simple" plugins, but there can be various unwanted effects, some of which are not simple or even hardly possible to track back. It might work with NCP, but since NCP is "complex" i would rather restart (the configuration reloading should work without problems). For a test server it may be ok, but as soon as issues arise, be sure to test it again with a clean restart and without any reloading.

@4lfalfa

I overlooked the note about no plugins .

This is not a known issue, neither can i reproduce it at present.

Where / how do you respawn? Inm the worlds spawn (vanilla), or in a bed, on what block types?

If you can systematically reproduce it, you might go to our jenkins and download the build 439 (the one after the recommended one) If you test alone, you can then set checks.debug to true:

checks:
  debug: true
  # ...

This will output a lot to the console. If you can reproduce it with that setting it would be very helpful to see the moving log.

Seems 439 has other issues with Survivalfly, but it shoudl be ok for testing the login issue. Alternatively you coudl use the recommended build and adit the BuildParameters.properties file inside of the jar, setting DEBUG_LEVEL=1 instead of 0. But first i would be interested in the circumstances (respawn location, blocks underneath/nearby).

@4lfalfa

Maybe has been fixed in the upcoming release (waiting for approval).

But basically a distance of 0 does not mean no violation, which may be not optimal. Naturally if you are flying without moving and would move the head, you will trigger this violation, because a normal client would fall if not on ground.

Technically this must be a case in which you are standing on some block which is not recognized as ground, thus any head turning will be interpreted as a move in air, consequently at some point it will trigger a violation.

The reason is totally uncertain, it could be a conflict with other plugins (Authentication plugins, NPC plugins like citizens if using the players names, plugins that can change blocks properties like SpoutPlugin if using custom blocks).

@jaimecamara

It is not lightweight. Main factor is the players moving, which needs a lot of attention to both cover exploits and not cause too many false positives at the same time.

How do you think it causes actual lag? Despite being heavy NCP is designed to run pretty smooth concerning performance. What you will see though is that if the server suffers a bigger lag spike anyway that NCP has to process all the delayed events coming in within the next server tick.

@NuggetFace

I suspect an offline mode plugin, since a null Location or null world on player join is something CraftBukkit would not do on its own, as far as i can judge it. Online would be better i guess.

@LordKainzo

Changes everywhere. Concerning velocity we need a moving trace. If you can reproduce your problem locally or on a test server, i would appreciate a log from the move with the setting

checks:
  debug: true

Use the latest recommended build for it, if it is done correctly, your console should be spammed with moving info and possibly other, so use it alone rather. This could help a lot with what happens with your issue, since we could not yet reproduce it. You did try to set "checks.moving.velocity.graceticks" to something higher like 30, 40 ?