75332450e3
Dear list, I have met this when I was using radosstriper C API. My program is roughly like this: rados_striper_aio_write rados_aio_flush rados_aio_wait_for_safe rados_aio_release rados_striper_destroy rados_ioctx_destroy rados_shutdown /Hangs here/ In most time, this works well, But the programm occasionally hangs forever. Output of gstack: Thread 1 (Thread 0x7fe0afba0760 (LWP 18509)): 0 0x000000330f20822d in pthread_join () from /lib64/libpthread.so.0 1 0x000000347566cea2 in Thread::join(void**) () from /usr/lib64/librados.so.2 2 0x00000034755ac535 in librados::RadosClient::shutdown() () from /usr/lib64/librados.so.2 3 0x0000003475592269 in rados_shutdown () from /usr/lib64/librados.so.2 4 0x0000000000402349 in main () Thread 4 (Thread 0x7fe0ab14d700 (LWP 18541)): 0 0x000000330f20e264 in __lll_lock_wait () from /lib64/libpthread.so.0 1 0x000000330f209508 in _L_lock_854 () from /lib64/libpthread.so.0 2 0x000000330f2093d7 in pthread_mutex_lock () from /lib64/libpthread.so.0 3 0x0000003475633af1 in Mutex::Lock(bool) () from /usr/lib64/librados.so.2 4 0x00000034755abd37 in librados::RadosClient::put() () from /usr/lib64/librados.so.2 5 0x0000003475592501 in librados::Rados::shutdown() () from /usr/lib64/librados.so.2 6 0x00007fe0afbba9f7 in libradosstriper::RadosStriperImpl::CompletionData::~CompletionData() () from /usr/lib64/libradosstriper.so.1 7 0x00007fe0afbbaad9 in libradosstriper::RadosStriperImpl::WriteCompletionData::~WriteCompletionData() () from /usr/lib64/libradosstriper.so.1 8 0x00007fe0afbc1d75 in RefCountedObject::put() () from /usr/lib64/libradosstriper.so.1 9 0x00007fe0afbc224d in libradosstriper::MultiAioCompletionImpl::safe_request(long) () from /usr/lib64/libradosstriper.so.1 10 0x00000034755c5ce8 in librados::C_AioSafe::finish(int) () from /usr/lib64/librados.so.2 11 0x00000034755a0e89 in Context::complete(int) () from /usr/lib64/librados.so.2 12 0x000000347564d4c8 in Finisher::finisher_thread_entry() () from /usr/lib64/librados.so.2 13 0x000000330f2079d1 in start_thread () from /lib64/libpthread.so.0 14 0x000000330eae886d in clone () from /lib64/libc.so.6 It is obvious that librados::Rados::shutdown is not a thread-safe function here. It will hang forever. The culprit of this is when CompletionData is released, it will first notify "rados_aio_wait_for_safe" to continue, and CompletionData will call put() to release other data. But if the main thread(Thread 1 here) runs fast enough, rados_striper_destroy will be executed before other thread(Thread 4 here)'s releasing refcnf. In this situation, main thread runs Rados::shutdown() while other thread runs Rados::shutdown() in the same time. My suggestion is to let RadosStriperImpl::aio_flush to block until all the CompletionData has been released. This makes sure other thread will never call rados_shutdown. |
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admin | ||
ceph-object-corpus@bb3cee6b85 | ||
debian | ||
doc | ||
examples | ||
fusetrace | ||
keys | ||
m4 | ||
man | ||
qa | ||
rpm | ||
share | ||
src | ||
systemd | ||
udev | ||
.gitignore | ||
.gitmodule_mirrors | ||
.gitmodules | ||
.mailmap | ||
.organizationmap | ||
.peoplemap | ||
AUTHORS | ||
autogen.sh | ||
ceph.spec.in | ||
ChangeLog | ||
CodingStyle | ||
configure.ac | ||
CONTRIBUTING.rst | ||
COPYING | ||
COPYING-LGPL2.1 | ||
deps.deb.txt | ||
deps.rpm.txt | ||
do_autogen.sh | ||
doc_deps.deb.txt | ||
Doxyfile | ||
INSTALL | ||
Makefile.am | ||
NEWS | ||
PendingReleaseNotes | ||
pom.xml | ||
README | ||
README.md | ||
SubmittingPatches |
============================================ Ceph - a scalable distributed storage system
Please see http://ceph.com/ for current info.
Contributing Code
Most of Ceph is licensed under the LGPL version 2.1. Some miscellaneous code is under BSD-style license or is public domain. The documentation is licensed under Creative Commons Attribution-ShareAlike (CC BY-SA). There are a handful of headers included here that are licensed under the GPL. Please see the file COPYING for a full inventory of licenses by file.
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We do not require assignment of copyright to contribute code; code is contributed under the terms of the applicable license.
Build Prerequisites
debian-based
The list of debian package dependencies can be found in deps.deb.txt:
sudo apt-get install `cat deps.deb.txt`
Note: libsnappy-dev and libleveldb-dev are not available upstream for natty, oneiric, and squeeze. Backports for Ceph can be found at ceph.com/debian-leveldb.
rpm-based
The list of RPM package dependencies can be found in deps.rpm.txt:
sudo yum install `cat deps.rpm.txt`
Building Ceph
Developers, please refer to the Developer Guide for more information, otherwise, you can build the server daemons, and FUSE client, by executing the following:
./autogen.sh
./configure
make
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Dependencies
The configure script will complain about any missing dependencies as it goes. You can also refer to debian/control or ceph.spec.in for the package build dependencies on those platforms. In many cases, dependencies can be avoided with --with-foo or --without-bar switches. For example,
./configure --with-nss # use libnss instead of libcrypto++
./configure --without-radosgw # do not build radosgw
./configure --without-tcmalloc # avoid google-perftools dependency
Building packages
You can build packages for Debian or Debian-derived (e.g., Ubuntu) systems with
sudo apt-get install dpkg-dev
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dpkg-buildpackage
For RPM-based systems (Red Hat, SUSE, etc.),
rpmbuild
Building the Documentation
Prerequisites
The list of package dependencies for building the documentation can be found in doc_deps.deb.txt:
sudo apt-get install `cat doc_deps.deb.txt`
Building the Documentation
To build the documentation, ensure that you are in the top-level `/ceph directory, and execute the build script. For example:
admin/build-doc