eth_syncing returns false when out of sync.

[CertHum-Jim]

Description

On a fully synced node (relay and parachain), if the relay chain falls behind, the parachain and frontier fall out of sync, only fully resyncing when the relay chain is back in sync. In this scenerio, calling the eth_syncing method returns false.

Steps to Reproduce

These steps were performed on a Moonbeam RPC with tracing files on Moonbeam client v0.37.0.

On a fully synced node:

1. Stop the client.
2. Delete the relay chain database.
3. Start the client
4. Issue the eth_syncing method

Expected vs. Actual Behavior

Because the relay has fallen out of sync the frontier db / parachain falls out of sync, and the Best block stops updating., It would be expected that eth_syncing would return true because the parachain wants to sync once the the relay is back in full sync. The actual behavior is that it returns false.

Environment

• Operating system: Ubuntu 22.04
• Project version/tag: moonbeam client v0.37.0
• Chain: Moonbeam

Logs, Errors or Screenshots

In this screenshot you can see that the bottom node is out of sync, and the Best block to be in sync is 5,957,616.

In the logs from the node you can see that the parachain is Idle because it considers the best block 5957567.

Apr 16 17:36:09 mynode moonbeam[242049]: 2024-04-16 17:36:09 [Relaychain] ⚙️  Syncing 1381.0 bps, target=#20371050 (23 peers), best: #825465 (0x2230…4fbb), finalized #825344 (0xfc94…04f5), ⬇ 478.3kiB/s ⬆ 8.8kiB/s
Apr 16 17:36:09 mynode moonbeam[242049]: 2024-04-16 17:36:09 [🌗] 💤 Idle (28 peers), best: #5957567 (0x8aae…9a66), finalized #5957546 (0xdba3…59ce), ⬇ 13.5kiB/s ⬆ 10.4kiB/s

In the below call you can see that eth_syncing returns false on the node.

mynode:~$ curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "eth_syncing"}' http://127.0.0.1:7777 | jq

  "jsonrpc": "2.0",
  "result": false,
  "id": 1
}