At some point, a player will be banned twice at the same time

[KOFTWAR]

Sorry about my English,Because it's not my mother tongue

What version of AdvancedBan (/AdvancedBan) are you using? 2.3.0 Latest

What kind of server do you have (Bungeecord/single server)? single server

What server version (/version) are you using? 1.8.8-PaperSpigot-445

Please provide the EXACT steps required to reproduce the problem... I can't exactly reproduce the problem because it occurs so randomly Using anti-cheat plugins to banned player will greatly increase the probability of triggering the problem

Any error/log post it through pastebin.com and link it here. (Also include /plugins/AdvancedBan/logs/latest.log) There is no log file

Add any additional information below. When I use the anti-cheat plugin to ban players, sometimes it happens that a player is banned twice. This problem hardly occurs under normal circumstances and no error is reported. I'm submitting this Issue to let you know that the problem exists, even though it doesn't really matter if you fix it or not And sorry about my English,Because it's not my mother tongue

[Hopefuls]

Could you elaborate the behaviour of "banning twice"? do you see multiple messages of the user being banned?

[KOFTWAR]

Could you elaborate the behaviour of "banning twice"? do you see multiple messages of the user being banned?

In the banlist there are two players banned information When I want to unban a player I need to type /unban twice

[KOFTWAR]

well,just like this

[KOFTWAR]

There are multiple player banned information in the banlist

[KOFTWAR]

This player can be banned up to five times.... I can also ban the player once by entering the command

[KOFTWAR]

[Hopefuls]

if the timestamps on both of these bans are equal, there is a small chance that it will accept both bans.

unsure about a fix as of now though, apart from having your anticheat only trigger once and not repeatedly

[A248]

Actually, this is a bug in AdvancedBan. The check for whether a player is already banned is not resilient enough to handle concurrent execution. So, although it's usually impossible to ban someone twice in AdvancedBan, running the command quickly enough allows you to bypass the check for an existing ban.

[A248]

The solution to this on AdvancedBan's side would be to use a database transaction and a sufficiently high transaction isolation level. That way, the check for the existing ban is atomic with respect to the new ban's addition.