v1.21.0-rc.0: unstable peers

[twoeths]

Describe the bug

Peer count is unstable on the beta mainnet node, I used to see it dropped to 35 while inbound peer is 0 or 1

it's likely due to Event Loop Lag on Network worker (which is only ~15ms on the stable mainnet node)

Expected behavior

• Peer count should be ~100 stably
• Inbound peers should be ~90 as in the stable mainnet node (or around that value)
• Event loop lag Network Worker should be ~15ms

Steps to reproduce

No response

Additional context

No response

Operating system

Linux

Lodestar version or commit hash

v1.21.0-rc.0

[twoeths]

This is on our unstable mainnet node

the issue started happening from around Jul 27 14:00:00 UTC so #5886 could be the root cause

[nflaig]

It does not look that bad on my mainnet nodes

mainnet-1

mainnet-2

mainnet-3

On all of the nodes I can also see an improved event loop lag metric

Let me know if there are other metrics to share that might be useful

[twoeths]

@nflaig it only happens on a test mainnet node because it subscribes to all subnets, so it has a lot of I/O load
I don't see the issue on our cip nodes too

[nflaig]

@nflaig it only happens on a test mainnet node because it subscribes to all subnets, so it has a lot of I/O load I don't see the issue on our cip nodes too

Right, that's likely it. Will enable it on one of my mainnet nodes as well now

[philknows]

After putting in rc.1 to beta, you can see the stabilization in some peer metrics here:

![Screenshot 2024-08-02

[twoeths]

attaching a network profile of cayman/yamux branch cc @wemeetagain

mainnet_yamux_network_thread_2024-08-06.cpuprofile.zip

there are so many dial errors in that branch

from the log:

grep -e "unexpected end of input" -rn beacon-2024-08-06.log | wc -l
19724

grep -e "REQUEST_ERROR_DIAL_ERROR" -rn beacon-2024-08-06.log | wc -l
14302

sample error stack trace does not seem relate to yamux

Aug-06 00:02:30.296[network]       ^[[36mverbose^[[39m: Req  error method=ping, version=1, encoding=ssz_snappy, client=NA, peer=16...kfMnnz, requestId=272488, code=REQUEST_ERROR_DIAL_ERROR, error=unexpected end of input
Error: unexpected end of input
    at Object.read (file:///usr/src/lodestar/node_modules/it-byte-stream/dist/src/index.js:86:31)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Object.read (file:///usr/src/lodestar/node_modules/it-length-prefixed-stream/dist/src/index.js:51:37)
    at async read (file:///usr/src/lodestar/node_modules/@libp2p/multistream-select/dist/src/multistream.js:22:17)
    at async Module.readString (file:///usr/src/lodestar/node_modules/@libp2p/multistream-select/dist/src/multistream.js:33:17)
    at async Module.select (file:///usr/src/lodestar/node_modules/@libp2p/multistream-select/dist/src/select.js:72:20)
    at async ConnectionImpl.newStream [as _newStream] (file:///usr/src/lodestar/node_modules/libp2p/dist/src/upgrader.js:330:50)
    at async ConnectionImpl.newStream (file:///usr/src/lodestar/node_modules/libp2p/dist/src/connection/index.js:94:24)
    at async file:///usr/src/lodestar/packages/reqresp/lib/request/index.js:57:26
    at async withTimeout (file:///usr/src/lodestar/packages/utils/lib/timeout.js:12:16)
Error: REQUEST_ERROR_DIAL_ERROR
    at file:///usr/src/lodestar/packages/reqresp/lib/request/index.js:67:23
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async sendRequest (file:///usr/src/lodestar/packages/reqresp/lib/request/index.js:55:24)
    at async ReqRespBeaconNode.sendRequest (file:///usr/src/lodestar/packages/reqresp/lib/ReqResp.js:109:13)
    at async collectExactOneTyped (file:///usr/src/lodestar/packages/beacon-node/lib/network/reqresp/utils/collect.js:10:22)
    at async PeerManager.requestPing (file:///usr/src/lodestar/packages/beacon-node/lib/network/peers/peerManager.js:340:31)

[twoeths]

issue was resolved because we reverted yamux enhancement