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https://issues.apache.org/jira/browse/TS-2767?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13987269#comment-13987269
]
Yunkai Zhang commented on TS-2767:
----------------------------------
Why not use {{string.clear()}} ? I bet it should be more efficient than
{{string.swap()}}
{code}
void
SpdyRequest::clear()
{
...
url.clear();
...
}
{code}
> ATS Memory Leak related to SPDY
> -------------------------------
>
> Key: TS-2767
> URL: https://issues.apache.org/jira/browse/TS-2767
> Project: Traffic Server
> Issue Type: Bug
> Components: SPDY
> Reporter: Sudheer Vinukonda
> Labels: SPDY_ATS, yahoo
> Fix For: 5.0.0
>
> Attachments: ts2767.diff
>
>
> During production testing of SPDY, we noticed ATS's memory quickly grows to
> about 20g RES and 31g VIRT and eventually becomes unresponsive. dstat shows a
> lot of disk/paging activity.
> Running Valgrind on a single request (using spdycat) shows the below possible
> leaks.
> {code}
> ==23000== 103 bytes in 1 blocks are possibly lost in loss record 3,133 of
> 3,823
> ==23000== at 0x4C285BC: operator new(unsigned long)
> (vg_replace_malloc.c:298)
> ==23000== by 0x72CC3C8: std::string::_Rep::_S_create(unsigned long,
> unsigned long, std::allocator<char> const&) (in
> /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x72CD19A: std::string::_Rep::_M_clone(std::allocator<char>
> const&, unsigned long) (in /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x72CD5EB: std::string::reserve(unsigned long) (in
> /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x72CDABE: std::string::append(std::string const&) (in
> /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x5D28DE: spdy_fetcher_launch(SpdyRequest*, TSFetchMethod)
> (basic_string.h:2165)
> ==23000== by 0x5D379D: spdy_on_ctrl_recv_callback(spdylay_session*,
> spdylay_frame_type, spdylay_frame*, void*) (SpdyCallbacks.cc:294)
> ==23000== by 0x715E9F: spdylay_session_on_syn_stream_received
> (spdylay_session.c:1782)
> ==23000== by 0x716BA6: spdylay_session_mem_recv (spdylay_session.c:2246)
> ==23000== by 0x716DD8: spdylay_session_recv (spdylay_session.c:2828)
> ==23000== by 0x5D0E57: spdy_default_handler(tsapi_cont*, TSEvent, void*)
> (SpdySM.cc:263)
> ==23000== by 0x6EC1A6: UnixNetVConnection::readSignalAndUpdate(int)
> (I_Continuation.h:146)
> ==23000==
> ==23000== 128 bytes in 1 blocks are possibly lost in loss record 3,256 of
> 3,823
> ==23000== at 0x4C285BC: operator new(unsigned long)
> (vg_replace_malloc.c:298)
> ==23000== by 0x5D3C8E: std::vector<std::pair<std::string, std::string>,
> std::allocator<std::pair<std::string, std::string> >
> >::_M_insert_aux(__gnu_cxx::__normal_iterator<std::pair<std::string,
> std::string>*, std::vector<std::pair<std::string, std::string>,
> std::allocator<std::pair<std::string, std::string> > > >,
> std::pair<std::string, std::string> const&) (new_allocator.h:89)
> ==23000== by 0x5D32CF: spdy_on_ctrl_recv_callback(spdylay_session*,
> spdylay_frame_type, spdylay_frame*, void*) (stl_vector.h:741)
> ==23000== by 0x715E9F: spdylay_session_on_syn_stream_received
> (spdylay_session.c:1782)
> ==23000== by 0x716BA6: spdylay_session_mem_recv (spdylay_session.c:2246)
> ==23000== by 0x716DD8: spdylay_session_recv (spdylay_session.c:2828)
> ==23000== by 0x5D0E57: spdy_default_handler(tsapi_cont*, TSEvent, void*)
> (SpdySM.cc:263)
> ==23000== by 0x6EC1A6: UnixNetVConnection::readSignalAndUpdate(int)
> (I_Continuation.h:146)
> ==23000== by 0x6DC779: SSLNetVConnection::net_read_io(NetHandler*,
> EThread*) (SSLNetVConnection.cc:294)
> ==23000== by 0x6E39F1: NetHandler::mainNetEvent(int, Event*)
> (UnixNet.cc:384)
> ==23000== by 0x71059E: EThread::process_event(Event*, int)
> (I_Continuation.h:146)
> ==23000== by 0x710DCA: EThread::execute() (UnixEThread.cc:269)
> ==23000==
> ==23000== 173 bytes in 5 blocks are possibly lost in loss record 3,303 of
> 3,823
> ==23000== at 0x4C285BC: operator new(unsigned long)
> (vg_replace_malloc.c:298)
> ==23000== by 0x72CC3C8: std::string::_Rep::_S_create(unsigned long,
> unsigned long, std::allocator<char> const&) (in
> /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x72CCDE4: ??? (in /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x72CCF32: std::basic_string<char, std::char_traits<char>,
> std::allocator<char> >::basic_string(char const*, std::allocator<char>
> const&) (in /usr/lib64/libstdc++.so.6.0.13)
> ==23000== by 0x5D32A2: spdy_on_ctrl_recv_callback(spdylay_session*,
> spdylay_frame_type, spdylay_frame*, void*) (stl_pair.h:101)
> ==23000== by 0x715E9F: spdylay_session_on_syn_stream_received
> (spdylay_session.c:1782)
> ==23000== by 0x716BA6: spdylay_session_mem_recv (spdylay_session.c:2246)
> ==23000== by 0x716DD8: spdylay_session_recv (spdylay_session.c:2828)
> ==23000== by 0x5D0E57: spdy_default_handler(tsapi_cont*, TSEvent, void*)
> (SpdySM.cc:263)
> ==23000== by 0x6EC1A6: UnixNetVConnection::readSignalAndUpdate(int)
> (I_Continuation.h:146)
> ==23000== by 0x6DC779: SSLNetVConnection::net_read_io(NetHandler*,
> EThread*) (SSLNetVConnection.cc:294)
> ==23000== by 0x6E39F1: NetHandler::mainNetEvent(int, Event*)
> (UnixNet.cc:384)
> ==23000==
> {code}
> Upon closer look, one possible issue might be the usage of std::string in the
> SpdyRequest object. The string objects created during spdy request processing
> may not be getting released correctly.
> Adding the below additional code in SpdyRequest::clear() to swap out the
> string objects with dummy/empty string objects seems to satisfy Valgrind to
> not report the above leaks any more. Am now trying this version on the
> production host to confirm further. Will keep posted.
> {code}
> void
> SpdyRequest::clear()
> {
> if (fetch_sm)
> TSFetchDestroy(fetch_sm);
> vector<pair<string, string> >().swap(headers);
> headers.clear();
> std::string().swap(url);
> std::string().swap(host);
> std::string().swap(path);
> std::string().swap(scheme);
> std::string().swap(method);
> std::string().swap(version);
> Debug("spdy", "****Delete Request[%" PRIu64 ":%d]", spdy_sm->sm_id,
> stream_id);
> }
> {code}
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