Deluge Forum

Hi all,

I'm using deluge 1.3.5 on a download machine, usually it works nice, but sometimes it hangs for a while and returns work.
When it hangs, no download nor upload is performed, the deluge process just run the CPU 100%, but no disk IO is performed as well(0% wa), I checked the DEBUG log, nothing is written.
After about one minute, everything goes well again.

I want to know why may this happen, or how can I debug further on this. Thanks.

bump

OS running deluged and how many torrents do you have in your list? How far apart are these CPU peaks?

About 200 torrents for about 3TB total.
It's irregular, but seems more likely to happen when change on torrent's state, (once I paused a torrent, then it hung, after it returned, I paused another, nothing more happened).
I wonder if it was on saving torrent's states, but I'm not sure.

I'm not familiar with twisted, I want to know how to attach a debugger when the deluged hangs, or we have anything else to know where and why this happens.

When it hangs, I tried to attach gdb and saw it's in libtorrent::disk_buffer_pool::free_buffer(char*), don't know what it is currently..

Program received signal SIGINT, Interrupt.
[Switching to Thread 0x7ff764148700 (LWP 1147)]
0x00007ff762b00303 in poll () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) info threads
Id Target Id Frame
4 Thread 0x7ff75fa31700 (LWP 1330) "deluged" 0x00007ff760ae3bf3 in libtorrent::disk_buffer_pool::free_buffer(char*) ()
from /usr/lib/libtorrent-rasterbar.so.6
3 Thread 0x7ff75f230700 (LWP 1331) "deluged" 0x00007ff762b0c353 in epoll_wait () from /lib/x86_64-linux-gnu/libc.so.6
2 Thread 0x7ff75ea2f700 (LWP 1333) "deluged" 0x00007ff763d20d84 in pthread_cond_wait@@GLIBC_2.3.2 ()
from /lib/x86_64-linux-gnu/libpthread.so.0
* 1 Thread 0x7ff764148700 (LWP 1147) "deluged" 0x00007ff762b00303 in poll () from /lib/x86_64-linux-gnu/libc.so.6
(gdb) thread 4
[Switching to thread 4 (Thread 0x7ff75fa31700 (LWP 1330))]
#0 0x00007ff760ae3bf3 in libtorrent::disk_buffer_pool::free_buffer(char*) () from /usr/lib/libtorrent-rasterbar.so.6
(gdb) bt
#0 0x00007ff760ae3bf3 in libtorrent::disk_buffer_pool::free_buffer(char*) () from /usr/lib/libtorrent-rasterbar.so.6
#1 0x00007ff760ae3e09 in libtorrent::disk_io_thread::free_piece(libtorrent::disk_io_thread::cached_piece_entry&, boost::unique_lock<boost::recursive_mutex>&) () from /usr/lib/libtorrent-rasterbar.so.6
#2 0x00007ff760ae62e5 in libtorrent::disk_io_thread::flush_expired_pieces() () from /usr/lib/libtorrent-rasterbar.so.6
#3 0x00007ff760ae8424 in libtorrent::disk_io_thread::operator()() () from /usr/lib/libtorrent-rasterbar.so.6
#4 0x00007ff75fe7bce9 in thread_proxy () from /usr/lib/libboost_thread.so.1.46.1
#5 0x00007ff763d1ce9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#6 0x00007ff762b0bcbd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#7 0x0000000000000000 in ?? ()

Have you enabled debug logging in deluge or you could change this log line to error to only see alerts from libtorrent in the log:

I suspect you might be having performance issues and getting something like the following:

http://www.rasterbar.com/products/libtorrent/manual.html wrote:outstanding_disk_buffer_limit_reached
This warning means that the number of bytes queued to be written to disk exceeds the max disk byte queue setting (session_settings::max_queued_disk_bytes). This might restrict the download rate, by not queuing up enough write jobs to the disk I/O thread. When this alert is posted, peer connections are temporarily stopped from downloading, until the queued disk bytes have fallen below the limit again. Unless your max_queued_disk_bytes setting is already high, you might want to increase it to get better performance.

Yes, I do recieve many "max outstanding disk writes reached" alerts. I changed max_queued_disk_bytes to 64MiB and it doesn't show me warnings again.

But the issue still not solved. And I'm confused because no disk write is performed in libtorrent::disk_buffer_pool::free_buffer(), what is it doing?!

Cas wrote:Have you enabled debug logging in deluge or you could change this log line to error to only see alerts from libtorrent in the log:

I suspect you might be having performance issues and getting something like the following:

http://www.rasterbar.com/products/libtorrent/manual.html wrote:outstanding_disk_buffer_limit_reached
This warning means that the number of bytes queued to be written to disk exceeds the max disk byte queue setting (session_settings::max_queued_disk_bytes). This might restrict the download rate, by not queuing up enough write jobs to the disk I/O thread. When this alert is posted, peer connections are temporarily stopped from downloading, until the queued disk bytes have fallen below the limit again. Unless your max_queued_disk_bytes setting is already high, you might want to increase it to get better performance.

Now it happened more often than a week ago, even when I'm adding torrent and even no operation. The upload and download just go down to 0, hold for several minutes, and go back.

Have you tried using libtorrent 0.16? Also what OS are you using?

I suggest you try asking on the libtorrent mailing list as the main dev will have more insight into this than myself.