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This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/30774/
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(Updated Feb. 17, 2015, 1:35 a.m.)
Review request for mesos, Adam B, Benjamin Hindman, Till Toenshoff, and Timothy
Chen.
Changes
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Put code into Setup() and TearDown() as much as possible. Now testing in HTTP
tests whether fetch contention occurs, i.e. whether FetcherProcess::_fetch()
gets called for all tasks before they can proceed with downloading anything. By
implication this exercises the code that sorts out what to do with each URI and
determines that some of them need to simply wait for another task to download
what they requested. This is further confirmed by checking the number of
requests to the HTTP server, which are now differentiated by URI.
Bugs: MESOS-2057, MESOS-2069, MESOS-2070, MESOS-2072, and MESOS-2074
https://issues.apache.org/jira/browse/MESOS-2057
https://issues.apache.org/jira/browse/MESOS-2069
https://issues.apache.org/jira/browse/MESOS-2070
https://issues.apache.org/jira/browse/MESOS-2072
https://issues.apache.org/jira/browse/MESOS-2074
Repository: mesos
Description
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Almost all of the functionality in epic MESOS-336. Downloaded files from
CommandInfo::URIs can now be cached in a cache directory designated by a slave
flag. This only happens when asked for by an extra flag in the URI and is thus
backwards-compatible. The cache has a size limit also given by a new slave
flag. Cache-resident files are evicted as necessary to make space for newly
fetched ones. Concurrent attempts to cache the same URI leads to only one
download. The fetcher program remains external for safety reasons, but is now
augmented with more elaborate parameters packed into a JSON object to implement
specific fetch actions for all of the above. Additional testing includes
fetching from (mock) HDFS and coverage of the new features.
Diffs (updated)
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include/mesos/fetcher/fetcher.proto facb87b92bf3194516f636dcc348e136af537721
include/mesos/mesos.proto 3a2921dff856d37455593dcbf7340aa537997d35
src/Makefile.am 0fe4809542a7d23785a221901947771320b43d52
src/hdfs/hdfs.hpp 968545d9af896f3e72e156484cc58135405cef6b
src/launcher/fetcher.cpp 5b2d86d1867b25bf71461fd73df91b089002325b
src/slave/constants.hpp 7717abd4f9a3bd6fdca6af2364864e374ce2e056
src/slave/containerizer/docker.hpp 70114dcef7a416ae904e95eb9ce365bcd866aebc
src/slave/containerizer/docker.cpp 813ddf8c98622748b2da1b739bf122387abc4c79
src/slave/containerizer/fetcher.hpp bfd98dbe16e2bd5df3e2c8e9b10e303654f33446
src/slave/containerizer/fetcher.cpp 6e6bce08d76bb8a5813c905e3ffeff9b2411fd6d
src/slave/containerizer/mesos/containerizer.hpp
b3aafe4efa9f3469d7a3fd39243ad66b46d6a54d
src/slave/containerizer/mesos/containerizer.cpp
fa40d47aee7803833bcde6cce1e86a21d7cf27d0
src/slave/flags.hpp f6033355d129f0013d39dd053455c936596bf159
src/slave/slave.cpp fff2d725fe49eee984d9151cfb2131202c47994f
src/tests/docker_containerizer_tests.cpp
8b212d4e6ed5a179ebadce1bdbbf3edde87d706c
src/tests/fetcher_cache_tests.cpp PRE-CREATION
src/tests/fetcher_tests.cpp fcbf7ad912f0b1b3d106a75a9dcb8213a0c69c07
src/tests/mesos.hpp 83a369968ab2403fa341829ac5d11f7243095190
src/tests/mesos.cpp 21a405366f56c963611324076efe775f85b9d9f7
src/tests/mock_hadoop.sh PRE-CREATION
Diff: https://reviews.apache.org/r/30774/diff/
Testing
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make check
--- longer Description: ---
-Replaces all other reviews for the fetcher cache except those related to
stout: 30006, 30033, 30034, 30036, 30037, 30039, 30124, 30173, 30614, 30616,
30618, 30621, 30626. See descriptions of those. In dependency order:
30033: Removes the fetcher env tests since these won't be needed any more when
the fetcher uses JSON in a single env var as a parameter. They never tested
anything that won't be covered by other tests anyway.
30034: Makes the code structure of all fetcher tests the same. Instead of
calling the run method of the fetcher directly, calling through fetch(). Also
removes all uses of I/O redirection, which is not really needed for debugging,
and thus the next patch can refactor fetch() and run(). (The latter comes in
two varieties, which complicates matters without much benefit.)
30036: Extends the CommandInfo::URI protobuf with a boolean "caching" field
that will later cause fetcher cache actions. Also introduces the notion of a
cache directory to the fetcher info protobuf. And then propagates these
additions throughout the rest of the code base where applicable. This includes
passing the slave ID all the way down to the place where the cache dir name is
constructed.
30037: Extends the fetcher info protobuf with "actions" (fetch directly
bypassing the cache, fetch through the cache, retrieve from the cache).
Switches the basis for dealing with uris to "items", which contain the uri, the
action, and potentially a cache file name. Refactors fetch() and run(), so
there is only one of each. Introduces about half of the actual cache logic,
including a hashmap of cache file objects for bookkeeping and basic operations
on it.
30039: Enables fetcher cache actions in the mesos fetcher program.
30006: Enables concurrent downloading into the fetcher cache. Reuse of download
results in the cache when multiple fetcher runs occur concurrently.
30614: This is to ensure that all this refactoring of fetcher code has not
broken HDFS fetching. Adds a test that exercises the C++ code paths in Mesos
and mesos-fetcher related to fetching from HDFS. Uses a mock HDFS client
written in bash that acts just like a real "hadoop" command if used in the
right limited way.
30124: Inserted fetcher cache zap upon slave startup, recovery and shutdown.
This implements recovery in an acceptable, yet most simple way.
30173: Created fetcher cache tests. Adds a new test source file containing a
test fixture and tests to find out if the fetcher cache works with a variety of
settings.
30616: Adds hdfs::du() which calls "hadoop fs -du -h" and returns a string that
contains the file size for the URI passed as argument. This is needed to
determine the size of a file on HDFS before downloading it to the fetcher cache
(to ensure there is enough space).
30621: Refactored URI type separation in mesos-fetcher. Moved the URI type
separation code (distinguishes http, hdfs, local copying, etc.) from
mesos-fetcher to the fetcher process/actor, since it is going to be reused by
download size queries when we introduce fetcher cache management. Also factored
out URI validation, which will be used the same way by mesos-fetcher and the
fetcher process/actor.
30626: Fetcher cache eviction. This happens when the cache does not have enough
space to accomodate upcoming downloads to the cache. Necessary provisions
included here:
- mesos-fetcher does not run until evictions have been successful
- Cache space is reserved while (async) waiting for eviction to succeed. If it
fails, the reservation gets undone.
- Reservations can be partly from available space, partly from evictions. All
math included :-)
- To find out how much space is needed, downloading has a prelude in which we
query the download size from the URI. This works for all URI types that
mesos-fetcher currently supports, including http and hdfs.
- Size-determination requests are now synchronized, too. Only one per URI in
play happens.
- There is cleanup code for all kinds of error situations. At the very end of
the fetch attempt, each list is processed for undoing things like space
reservations and eviction disabling.
- Eviction gets disabled for URIs that are currently in use, i.e. the related
cache files are. We use reference counting for this, since there may be
concurrent fetch attempts using the same cache files.
Thanks,
Bernd Mathiske
