electrs crashes while indexing mainnet with "Too many open files"

Electrs new-index works fine for testnet but while syncing mainnet, errors out with -

(Truncated log)

TRACE - skipping block 0000000000000000001a871a0c81fe392e9d90562e702eddd2835e27da815f1d
TRACE - skipping block 0000000000000000001198ed4b9090ef67acebc8ca517bdcd67efc930e554b6c
TRACE - skipping block 0000000000000000001c02b01cb173dc33cd901d0842be6f331037c03b1b1afa
TRACE - skipping block 000000000000000000131227a7c21c0c247b5ee30aeffbd1f9ccba6038d071d5
TRACE - skipping block 0000000000000000000c99cf30cb7609a3d3e1bc6b65c6360b03130e34b2f150
TRACE - fetched 9 blocks
DEBUG - writing 98889 rows to RocksDB { path: "./db/mainnet/newindex/txstore" }, flush=Disable
DEBUG - starting full compaction on RocksDB { path: "./db/mainnet/newindex/txstore" }
DEBUG - finished full compaction on RocksDB { path: "./db/mainnet/newindex/txstore" }
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Error { message: "IO error: While open a file for random read: ./db/mainnet/newindex/txstore/000938.sst: Too many open files" }', src/libcore/result.rs:997:5
Aborted (core dumped)

Also, the size of ./db is ~325GB. Is this normal?

[clarkmoody]

The issue on my system turned out to be caused by systemd overriding system wide limits with a “sane” default. Was resolved by setting LimitNOFILE with a higher value in the electrs service file.

@setpill Excellent, thanks! Running via systemd here.

Might be nice to make a note of this in the docs 😉

[dongcarl]

Here’s how I got around this on the command line:

sudo prlimit --nofile=65536 sudo -u "$(id -u)" -g "$(id -g)" cargo blah blah wtv

The first sudo makes us root and gives us access to modify file limits, the second sudo brings us back to our original user to execute cargo properly