litecoind keeps on exiting after restart

[kilrau]

Offshoot from #38 and reason why xud can't connect to litecoind after restart of container/machine:

• rm -rf ~/.xud-docker/testnet/data/litecoind - resync - all is good
• but once litecoind was stopped or the machine rebooted, litecoind container keeps on exititing because it can't read some block data
• it looks like docker stop doesn't manage to gracefully shutdown litecoind

[reliveyy]

https://bitcoin.stackexchange.com/questions/8787/failed-to-read-block
bitcoin/bitcoin#8081

The solution I can find is using command line option -reindex. But with this option litecoind will re-sync from the beginning. I don't think it's a good solution for users.
And I also notice that bitcoind doesn't have this broken data crashing problem.

[kilrau]

I'd like to test something:

1. delete data/litcoind, sync testnet from scratch, bash into litecoind container and shut down gracefully via rpc. Then down container.
2. docker-compose up -d litecoind. See if it works.

[kilrau]

Adding a fresh litecoind log here soon (resyncing).

[kilrau]

In some tests we verified that litecoind's graceful shutdown is triggered on docker stop litecoind but looks like it doesn't finish all it has to do before docker kills. Trying stop_grace_period: 1m in docker-compose.yml .

[kilrau]

Problem: host reboot or docker stop litecoind does not care about the docker-compose yml file.

Patching the entry script should be the way to go:
https://medium.com/@manish_demblani/docker-container-uncaught-kill-signal-d5ed22698293

Let's do it for all containers to be on the safe side.

[kilrau]

Tested:

t0 litecoind syncing

ltc Syncing 0.83% (8347/1003999)

t1 docker stop

> docker stop 3d68ba19d202
3d68ba19d202

t2 log shows complete shutdown

litecoind_1  | Stopping PID 6
litecoind_1  | 2019-06-19T09:53:07Z tor: Thread interrupt
litecoind_1  | 2019-06-19T09:53:07Z Shutdown: In progress...
litecoind_1  | 2019-06-19T09:53:07Z torcontrol thread exit
litecoind_1  | 2019-06-19T09:53:07Z addcon thread exit
litecoind_1  | 2019-06-19T09:53:07Z opencon thread exit
litecoind_1  | 2019-06-19T09:53:07Z net thread exit
litecoind_1  | 2019-06-19T09:53:07Z msghand thread exit
litecoind_1  | 2019-06-19T09:53:07Z scheduler thread interrupt
litecoind_1  | 2019-06-19T09:53:07Z Dumped mempool: 3e-06s to copy, 0.003441s to dump
litecoind_1  | 2019-06-19T09:53:15Z Shutdown: done

t3 docker-compose up -d litecoind

Syncing continues without issues (ltc Syncing 1.45% (16220/1113654))

t4 YAY