View Issue Details

IDProjectCategoryView StatusLast Update
0002362Spring engineGeneralpublic2011-08-02 20:13
Reporterabma Assigned Toabma  
PrioritynormalSeveritycrashReproducibilityhave not tried
Status resolvedResolutionfixed 
Product Version0.82.7.1 
Summary0002362: desync in online game with gentoo x86_64
Descriptionsee attached files
TagsNo tags attached.
Attached Files
synced-infolog.txt (Attachment missing)
synced_20110220_211241_DesertSiege_v2_0.82.7.sdf (Attachment missing)
danchan_desynced_infolog.txt (Attachment missing)
danchan_desynced_20110220_211240_DesertSiege_v2_0.82.7.sdf (Attachment missing)
Checked infolog.txt for Errors

Relationships

related to 0002338 resolvedabma Playing online I always experience desync 

Activities

dansan

2011-02-21 01:32

reporter   ~0006415

I just noticed that around the time of the game a p2p client was running in my network. I have no idea how much bandwidth it used...

Anyways: if the desync looks like it could be explained by network latency (no idea if that can happen or seen in the log) than that is a possible explanation.

hoijui

2011-03-26 11:24

reporter   ~0006511

no, that is not possible. desync can not be caused by network problems.

abma

2011-03-26 12:17

administrator   ~0006513

maybe related? 0002338

zerver

2011-03-26 18:09

reporter   ~0006516

hm, why cannot network corruption cause a desync? network corruption isn't that unusual and spring provides no extra checksum protection iirc.

hoijui

2011-04-03 10:04

reporter   ~0006526

because the underlying protocol does that for us.

abma

2011-04-03 22:03

administrator   ~0006531

Last edited: 2011-04-03 22:05

just an idea: try to disable checksum offloading, by:
sudo ethtool --offload eth0 rx off tx off

dansan

2011-04-04 10:07

reporter   ~0006532

You mean the server or me?

daniel@maya ~ $ sudo ethtool --show-offload eth0
Offload parameters for eth0:
rx-checksumming: on
tx-checksumming: on
scatter-gather: on
tcp-segmentation-offload: on
udp-fragmentation-offload: off
generic-segmentation-offload: on
generic-receive-offload: on
large-receive-offload: off
rx-vlan-offload: off
tx-vlan-offload: off
ntuple-filters: off
receive-hashing: on

So it's on, and I could disable it, but I'd need a reason to do so, because the problem is: 1. I have no problems with other apps/protocols and 2. I cannot reproduce the desync (except by replaying the game). I get desyncs only like once in three month. Maybe you wanted to tell macbeth/0002338 to do that?

abma

2011-04-04 12:32

administrator   ~0006533

Last edited: 2011-04-04 12:36

most other apps mostly don't use udp + their pakets are bigger. you can only desync in network games. desync means, your game and the game on an other host aren't in "sync"...

just google for "udp offload checksum error" or something like that..

there are only 2 guys having this problem, so it seems, that its a very special problem.


this bug could also be only a compiler-issue...

dansan

2011-04-04 14:08

reporter   ~0006534

> you can only desync in network games
Right... what I saw in the replay was only the message :)

Where to go from here? I don't know how to reproduce the problem - not even on the same day on the same server...
In case it happens sometimes - what exactly should I do (besides from infolog+mantis)?

abma

2011-06-05 16:45

administrator   ~0006704

which boost-version do you have installed?

dansan

2011-06-05 21:23

reporter   ~0006706

Back then:
Thu Feb 3 14:07:31 2011 >>> dev-libs/boost-1.42.0-r2
Sat Feb 5 01:47:19 2011 >>> games-strategy/spring-0.82.7.1
Now:
Sat May 7 21:38:58 2011 >>> dev-libs/boost-1.46.1
Tue May 17 23:37:46 2011 >>> games-strategy/spring-0.82.7.1

I haven't had a desync for months now.

abma

2011-07-31 16:49

administrator   ~0007155

Last edited: 2011-07-31 16:50

that means with 1.42 you had desyncs and with 1.46 it works?

dansan

2011-08-01 02:02

reporter   ~0007173

Cannot say... sorry... it was very rare then, and almost never happens now... not enough data....

Want me to investigate? I can compile spring against dev-libs/boost-1.42.0-r2 and see for some days/weeks if it makes any difference.

abma

2011-08-01 11:08

administrator   ~0007174

i tested for myself, 1.46 seems to desync, too.

was stdlibc++ updated? (part of g++) if so, from wich version to wich version?

as these desyncs where so rare... its hard to find the cause then :-/

abma

2011-08-02 20:13

administrator   ~0007203

Last edited: 2011-08-02 20:13

desyncs should be fixed now in spring/master:
https://github.com/spring/spring/commit/46a073e78f5c3092b0a59cb05e10adb5732ce066

Issue History

Date Modified Username Field Change
2011-02-20 21:27 abma New Issue
2011-02-20 21:27 abma File Added: synced-infolog.txt
2011-02-20 21:27 abma File Added: synced_20110220_211241_DesertSiege_v2_0.82.7.sdf
2011-02-20 21:37 dansan File Added: danchan_desynced_infolog.txt
2011-02-20 21:37 dansan File Added: danchan_desynced_20110220_211240_DesertSiege_v2_0.82.7.sdf
2011-02-21 01:32 dansan Note Added: 0006415
2011-03-26 11:24 hoijui Note Added: 0006511
2011-03-26 12:17 abma Note Added: 0006513
2011-03-26 13:55 abma Severity minor => crash
2011-03-26 18:09 zerver Note Added: 0006516
2011-03-31 00:54 abma Relationship added related to 0002338
2011-04-03 10:04 hoijui Note Added: 0006526
2011-04-03 22:03 abma Note Added: 0006531
2011-04-03 22:05 abma Note Edited: 0006531
2011-04-04 10:07 dansan Note Added: 0006532
2011-04-04 12:32 abma Note Added: 0006533
2011-04-04 12:33 abma Note Edited: 0006533
2011-04-04 12:34 abma Note Edited: 0006533
2011-04-04 12:35 abma Note Edited: 0006533
2011-04-04 12:36 abma Note Edited: 0006533
2011-04-04 12:36 abma Note Edited: 0006533
2011-04-04 14:08 dansan Note Added: 0006534
2011-06-05 16:45 abma Note Added: 0006704
2011-06-05 21:23 dansan Note Added: 0006706
2011-07-31 16:49 abma Note Added: 0007155
2011-07-31 16:50 abma Note Edited: 0007155
2011-08-01 02:02 dansan Note Added: 0007173
2011-08-01 11:08 abma Note Added: 0007174
2011-08-02 20:13 abma Note Added: 0007203
2011-08-02 20:13 abma Status new => resolved
2011-08-02 20:13 abma Resolution open => fixed
2011-08-02 20:13 abma Assigned To => abma
2011-08-02 20:13 abma Note Edited: 0007203