Parity light client hardcoded sync

[hsnhrn]

Before filing a new issue, please provide the following information.

• Parity Ethereum version: 2.4.0-unstable-af7dc3676-20190215/arm-linux-gnu/rustc1.32.0
• Operating system: armv7
• Installation: built from source
• Fully synchronized: no
• Network: ethereum / Tobalaba
• Restarted: yes

I need to sync my parity light client from a hardcoded block. I synced the light client fully in a Debian image and exported the hardcoded sync. I then pasted it in the chain spec file of a desired node and ran the light client. But it gave and error below

Stage 4 block verification failed for #10594306 (0x5577…b88b)
Error: Error(Engine(NotProposer(Mismatch { expected:
0x4ba15b56452521c0826a35a6f2022e1210fc519b, found:
0x5f93cc6c9f13f80a5bbc1bb1e0520100f8887ce9 })), State { next_error: None,
backtrace: InternalBacktrace { backtrace: None } })
and stuck at block number #10594305.. Is there something went wrong during export of the block number or is there anything wrong with this node? Thanks a lot!

[jam10o-new]

It may just be a problem with the peers you've discovered.

I would try wiping your nodes.json file (in chains/your chain/network) and restarting until your sync continues.

[hsnhrn]

Thanks for your reply.I tried it for few times.. but no luck..
any other suggestions plz?

Node also give this as well..

Validator 0x5f93…7ce9 could not be reported No full client!

[jam10o-new]

Can I ask how you exported the hard-coded sync, and how certain you are that your full node had a healthy chain in the first place?

Also, after doing that I would have added the "full" node that exported the headers as a reserved peer of the light node.

Validator 0x5f93…7ce9 could not be reported No full client!

This sounds like there's a misbehaving validator on the network, it's not really related to the issue you are seeing here, but is very likely the general cause - there's nothing you can really do other than get past the bad blocks.

[hsnhrn]

I sync the light node in my debian PC and get the exported sync by running the command parity --light export-hardcoded-sync.
Yes you are right that we can not be sure if the node has healthy chain or not. I am just assuming it to be a healthy chain..

[Tbaut]

I've had the same issue on Kovan with a full light sync. My node is running totally fine, I can export the headers, but when I use the genesis that I've created using these headers, I get:

./target/release/parity --chain ~/github/paritytech/parity-ethereum/ethcore/res/ethereum/kovan.json --light -d ~/Desktop/light-test
2019-10-25 15:59:44  Starting Parity-Ethereum/v2.7.0-unstable-acf7c48d7-20191023/x86_64-linux-gnu/rustc1.37.0
2019-10-25 15:59:44  Keys path /home/thib/Desktop/light-test/keys/kovan
2019-10-25 15:59:44  DB path /home/thib/Desktop/light-test/chains_light/kovan/db/9bf388941c25ea98
2019-10-25 15:59:44  Running in experimental Light Client mode.
2019-10-25 15:59:44  Debug API is not available in light client mode.
2019-10-25 15:59:44  Debug API is not available in light client mode.
2019-10-25 15:59:46  verify_block_external: bad proposer for step: 392999321
2019-10-25 15:59:46  Stage 4 block verification failed for #14368770 (0x9846…f396)
Error: Engine(NotProposer(Mismatch { expected: 0x4ed9b08e6354c70fe6f8cb0411b0d3246b424d6c, found: 0x03801efb0efe2a25ede5dd3a003ae880c0292e4d }))
2019-10-25 15:59:49  Syncing #14368769 0xcddb…aa7c     0.0 hdr/s      0+    0 Qed   5/50 peers   664 bytes cache 0 bytes queue  RPC:  0 conn,    0 req/s,    0 µs
2019-10-25 15:59:49  Public node URL: enode://a42f0059e141f7e031f2f4a40ca02fdada0d4ef82deb43cd2c745b5c82a9011e1e5c37e736a9836b5439e5ce1f224e2acd7129c6ddccaef4a7a8b398bc2646d4@192.168.10.201:30303
2019-10-25 15:59:54  Syncing #14368769 0xcddb…aa7c     0.0 hdr/s      0+    0 Qed   3/50 peers   664 bytes cache 0 bytes queue  RPC:  0 conn,    0 req/s,    0 µs
2019-10-25 15:59:59  Syncing #14368769 0xcddb…aa7c     0.0 hdr/s      0+    0 Qed   4/50 peers   664 bytes cache 0 bytes queue  RPC:  0 conn,    0 req/s,    0 µs
2019-10-25 16:00:04  Syncing #14368769 0xcddb…aa7c     0.0 hdr/s      0+    0 Qed   8/50 peers   664 bytes cache 0 bytes queue  RPC:  0 conn,    0 req/s,    0 µs
2019-10-25 16:00:09  Syncing #14368769 0xcddb…aa7c     0.0 hdr/s      0+    0 Qed   7/50 peers   664 bytes cache 0 bytes queue  RPC:  0 conn,    0 req/s,    0 µs

here is the kovan.json that I created. Using 2.7.0 master as of yesterday.

Note that comparing the hash of the latest #14368769 0xcddb…aa7c aligns with what Etherscan or blockscout have.
^ this block is 4h old at the time of writing.