rqbit spends significant disk I/O to save DHT cache #310
Description
I'm running rqbit on linux "server" as service (using latest Docker image] and I see significant disk I/O related to rqbit, even if nothing is "happening" - no active torrents.
Command is simple/default: /bin/rqbit server start /home/rqbit/downloads
rqbit is far most active process for disk IO - disk writes - see iotop - accumulated over 10 secs:
PID PRIO USER DISK READ DISK WRITE> COMMAND
2528676 be/4 root 0.00 B 2021.00 K rqbit server start /home/rqbit/downloads
371 be/3 root 0.00 B 356.00 K systemd-journald
3261 be/4 999 0.00 B 46.00 K postgres: stats collector process
with iostat it looks like ongoing write is about 200 KB/s continuously
Looking with strace what's going on:
$ sudo strace -p 2528676 -f -e trace=file,write
strace: Process 2528676 attached with 6 threads
[pid 2528698] open("/home/rqbit/cache/com.rqbit.dht/dht.json.tmp.1", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE|O_CLOEXEC, 0666) = 19
[pid 2528698] write(19, "{\"addr\":\"0.0.0.0:55022\",\"table\":"..., 8163) = 8163
[pid 2528698] write(19, "3caad6911d8e95475da6a6dc498ab3d8"..., 8191) = 8191
...
[pid 2528698] rename("/home/rqbit/cache/com.rqbit.dht/dht.json.tmp.1", "/home/rqbit/cache/com.rqbit.dht/dht.json") = 0
[pid 2528698] write(19, "2d721ae6fa4a2a24f2bd3e1886e91371"..., 315) = 315
...
File /home/rqbit/cache/com.rqbit.dht/dht.json is rewritten every ~ 3 second. Size of file is ~ 200 KB.
And this generates notable load to disks.
I have not looked for CLI options, if it can be disabled - will look, but as default option it seem to me bit aggressive from disk IO perspective.