cosmosdump is a simple debug tool for Cosmos nodes.
When you write a non-deterministic code, such as using time.Time() or generating random values, you may encounter a consensus error like this:
ERR CONSENSUS FAILURE!!! err="+2/3 committed an invalid block: wrong Block.Header.AppHash. Expected 5FC641EE89BB0579BE17943917CD5A7CD3C918E1C527247AFAD022C9755200C4, got 4F5E48398E8A0845DB8A7209FAFFD81C71F51F84A0E21C88059DB1C13650EF72"
By default, Cosmos provides no information about which store's differences are causing this AppHash mismatch, making debugging a challenging task.
cosmosdump addresses this issue. It's a simple script that dumps all key-value pairs from a Cosmos node's database. This allows you to compare and identify which keys are responsible for this discrepancy.
# install
go install
# dump
cosmosdump <dataDir> <height(optional)>
Suppose you encounter a consensus error at block height 100. You can compare data from two different chains as follows:
$ cosmosdump ~/.my-chain1 100 > chain1.dump
$ cosmosdump ~/.my-chain2 100 > chain2.dump
$ diff chain1.dump chain2.dump -c1
*** dump1 2023-12-02 09:41:05.773711981 +0900
--- dump2 2023-12-02 09:41:09.943511826 +0900
***************
*** 1,3 ****
! dir: /home/totegamma/.my-chain1
! latestVersion: 175
targetHeight: 101
--- 1,3 ----
! dir: /home/totegamma/.my-chain2
! latestVersion: 101
targetHeight: 101
***************
*** 262,264 ****
key(ascii): mymodule MyModule/value/hoge/
! value(hex): AAAAAA
--- 262,264 ----
key(ascii): mymodule MyModule/value/hoge/
! value(hex): BBBBBB
Exit status: 1
[totegamma@09:41]~/tmp$
From this comparison, you can deduce that the key MyModule/value/hoge/ is the source of the issue.
In most cases, the values are protobuf-encoded. Therefore, you can inspect them using tools like Protobuf Decoder