Hi, not sure whether this is related to mod_http2 v1.10.0 or is something else.
I've seen two servers where old httpd processes get stuck. server-status looks like this: Slot PID Stopping Connections Threads Async connections total accepting busy idle writing keep-alive closing 0 27399 yes (old gen) 3 no 0 0 0 0 0 1 879 yes (old gen) 1 no 0 0 0 0 0 2 11609 yes (old gen) 2 no 0 0 0 0 0 3 9142 yes (old gen) 2 no 0 0 0 0 0 4 11098 yes (old gen) 3 no 0 0 0 0 0 5 27400 yes (old gen) 1 no 0 0 0 0 0 6 16445 yes (old gen) 1 no 0 0 0 0 0 7 16446 yes (old gen) 1 no 0 0 0 0 0 8 7388 yes (old gen) 4 no 0 0 0 0 0 9 24072 yes (old gen) 2 no 0 0 0 0 0 10 28673 yes (old gen) 2 no 0 0 0 0 0 11 7389 yes (old gen) 3 no 0 0 0 0 0 12 11075 yes (old gen) 8 no 0 0 0 0 0 13 11076 yes (old gen) 6 no 0 0 0 0 0 14 26613 yes (old gen) 5 no 0 0 0 0 0 15 737 no 1 yes 8 192 0 0 1 16 739 no 3 yes 13 187 0 0 1 17 24059 yes (old gen) 1 no 0 0 0 0 0 18 26002 yes (old gen) 7 no 0 0 0 0 0 19 26003 yes (old gen) 4 no 0 0 0 0 0 20 2473 yes (old gen) 2 no 0 0 0 0 0 21 3010 yes (old gen) 4 no 0 0 0 0 0 22 8847 yes (old gen) 3 no 0 0 0 0 0 Sum 23 21 69 21 379 0 0 2 bt of such a process shows: (gdb) bt #0 0x00007f5df74f64db in pthread_join () from /lib/x86_64-linux-gnu/libpthread.so.0 #1 0x00007f5df77314ab in apr_thread_join (retval=0x7ffc0878f424, thd=0x7f5d580dc7c8) at threadproc/unix/thread.c:217 #2 0x0000555c1dc9deb3 in join_workers (listener=0x7f5d580dc7c8, threads=0x555c1f3d4310) at event.c:2376 #3 0x0000555c1dc9e25a in child_main (child_num_arg=0, child_bucket=524108560) at event.c:2574 #4 0x0000555c1dd68fe0 in make_child (s=0x7f5cf673c9d0, slot=0, bucket=0) at event.c:2646 #5 0x0000555c1dd6950c in server_main_loop (num_buckets=<optimized out>, remaining_children_to_start=<optimized out>) at event.c:2916 #6 event_run (_pconf=0x7f5cf673c9d0, plog=0x0, s=0xc8) at event.c:3035 #7 0x0000555c1dca642e in ap_run_mpm (pconf=0x555c1f031138, plog=0x555c1f072bb8, s=0x555c1f0625a8) at mpm_common.c:94 #8 0x0000555c1dc9ed15 in main (argc=2, argv=0x7ffc0878f828) at main.c:783 An strace is like this one: strace -ff -p 32375 Process 32375 attached with 303 threads [pid 856] futex(0x7f5ce8003c60, FUTEX_WAIT_PRIVATE, 2, NULL <unfinished ...> [pid 486] futex(0x555c1f3b17d4, FUTEX_WAIT_PRIVATE, 1, NULL <unfinished ...> [pid 857] epoll_wait(14, <unfinished ...> [pid 484] futex(0x555c1f3b174c, FUTEX_WAIT_PRIVATE, 1, NULL <unfinished ...> [pid 482] futex(0x555c1f3b16c4, FUTEX_WAIT_PRIVATE, 1, NULL <unfinished ...> [pid 481] futex(0x555c1f3b163c, FUTEX_WAIT_PRIVATE, 1, NULL <unfinished ...> ....... Greets, Stefan