removeElement panics with nil interface conversion

[limhyesook]

Hello, I'm facing intermittent issues with using simplelru under high load. Here is the error:

Apr 22 05:56:59 server1 erigon[4187823]: panic: interface conversion: interface {} is nil, not *simplelru.entry
Apr 22 05:56:59 server1 erigon[4187823]: goroutine 355 [running]:
Apr 22 05:56:59 server1 erigon[4187823]: github.com/hashicorp/golang-lru/simplelru.(*LRU).removeElement(0x16ec740, 0xc0009cb608)
Apr 22 05:56:59 server1 erigon[4187823]: github.com/hashicorp/golang-lru@v0.5.5-0.20210104140557-80c98217689d/simplelru/lru.go:172 +0x107
Apr 22 05:56:59 server1 erigon[4187823]: github.com/hashicorp/golang-lru/simplelru.(*LRU).removeOldest(0x15d7080)
Apr 22 05:56:59 server1 erigon[4187823]: github.com/hashicorp/golang-lru@v0.5.5-0.20210104140557-80c98217689d/simplelru/lru.go:165 +0x34
Apr 22 05:56:59 server1 erigon[4187823]: github.com/hashicorp/golang-lru/simplelru.(*LRU).Add(0xc0036d5b60, {0x1567300, 0xc01e20ee10}, {0x15ad680, 0x371f460})
Apr 22 05:56:59 server1 erigon[4187823]: github.com/hashicorp/golang-lru@v0.5.5-0.20210104140557-80c98217689d/simplelru/lru.go:67 +0x394
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib/txpool.(*TxPool).discardLocked(0xc000200180, 0xc012f77ef0, 0x4)
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib@v0.0.0-20220401025652-224f0c9dc058/txpool/pool.go:1063 +0x15a
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib/txpool.(*TxPool).addLocked(0xc000200180, 0xc01c355a90)
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib@v0.0.0-20220401025652-224f0c9dc058/txpool/pool.go:1038 +0x2c5
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib/txpool.addTxs(0x105cc63, {0x28a5fe8, 0xc01e015938}, 0xc001c65a70, {{0xc010ff5800, 0x42, 0x80}, {0xc0153eec00, 0x528, 0x600}, ...}, ...)
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib@v0.0.0-20220401025652-224f0c9dc058/txpool/pool.go:905 +0x4a4
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib/txpool.(*TxPool).processRemoteTxs(0xc000200180, {0x28c2d58, 0xc0010eb480})
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib@v0.0.0-20220401025652-224f0c9dc058/txpool/pool.go:507 +0x4bc
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib/txpool.MainLoop({0x28c2d58, 0xc0010eb480}, {0x28cc1a8, 0xc001d92280}, {0x1ad4ccb667b585ab, 0x13748a941b4512d3}, 0xc000200180, 0xc0006ae780, 0xc0003571c0, 0xc0005ba150, ...)
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon-lib@v0.0.0-20220401025652-224f0c9dc058/txpool/pool.go:1327 +0x565
Apr 22 05:56:59 server1 erigon[4187823]: created by github.com/ledgerwatch/erigon/eth.New
Apr 22 05:56:59 server1 erigon[4187823]: github.com/ledgerwatch/erigon/eth/backend.go:475 +0x3368

Panic happens at this line I believe:
kv := e.Value.(*entry)

Is it because I'm misusing library in some way?

[arrony135]

simplelru is not thread safe, please make sure to protect by lock when Add or Get

[AskAlexSharov]

can close this issue. yes, it was thread-safety thing on our side.