Re: remote pg_dump hangs always at same table

Axel Rau <Axel(dot)Rau(at)chaos1(dot)de> writes:
> client:
> #0 0x9405de0e in poll$UNIX2003 ()
> #1 0x00044cfa in pqSocketCheck ()
> #2 0x00045101 in pqWaitTimed ()
> #3 0x00045167 in pqWait ()
> #4 0x0004b9b3 in pqGetCopyData3 ()
> #5 0x0001295f in dumpTableData_copy ()
> #6 0x00022a19 in _PrintTocData ()
> #7 0x0001ecd1 in RestoreArchive ()
> #8 0x00015daa in main ()
> -----------
> server:
> #0 0x00000008014b3d5a in read () from /lib/libc.so.7
> #1 0x00000008012c7760 in read () from /lib/libthr.so.3
> #2 0x0000000800e91142 in BIO_new_socket () from /lib/libcrypto.so.5
> #3 0x000000000053039e in secure_write ()
> #4 0x0000000800f0d9df in BIO_read () from /lib/libcrypto.so.5
> #5 0x0000000800cdfe60 in ssl3_read_n () from /usr/lib/libssl.so.5
> #6 0x0000000800ce0352 in ssl3_read_bytes () from /usr/lib/libssl.so.5
> #7 0x0000000800ce6f11 in ssl3_get_message () from /usr/lib/libssl.so.5
> #8 0x0000000800cd1989 in ssl3_get_client_hello () from /usr/lib/
> libssl.so.5
> #9 0x0000000800cd263c in ssl3_accept () from /usr/lib/libssl.so.5
> #10 0x00000000005301af in secure_write ()
> #11 0x0000000000535235 in pq_setkeepalivesidle ()
> #12 0x0000000000535363 in pq_flush ()
> #13 0x000000000053540c in pq_putmessage ()
> #14 0x00000000004d62c8 in CreateCopyDestReceiver ()
> #15 0x00000000004d648a in CreateCopyDestReceiver ()
> #16 0x00000000004d8076 in CreateCopyDestReceiver ()
> #17 0x00000000004da398 in DoCopy ()

Hmm. This backtrace is not tremendously trustworthy (it'd be better if
you had debug symbols installed for these libraries) but it seems fairly
clear that the backend is stuck trying to transmit data to the client,
rather than in any internal operation. And evidently you're using SSL.
I wonder whether this is a case of the SSL-renegotiation-broken-by-
security-"fixes" issue. Have you recently updated the openssl library
on either the client or the server? Is it practical for you to try a
dump across a non-SSL connection to see if that works, or is your
network too insecure for that? (Possibly you could try dumping
across an SSH tunnel instead of a direct connection, if so.)

If I'm right in blaming this on broken SSL renegotiation, you'll want
to update to Monday's minor releases, which will have a knob to allow
SSL renegotiation to be disabled.

regards, tom lane