| Index: third_party/gsutil/gslib/addlhelp/prod.py
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| diff --git a/third_party/gsutil/gslib/addlhelp/prod.py b/third_party/gsutil/gslib/addlhelp/prod.py
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| deleted file mode 100644
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| index 1dabbf6c6d196109678fc283bd9e31f7e109d921..0000000000000000000000000000000000000000
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| --- a/third_party/gsutil/gslib/addlhelp/prod.py
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| +++ /dev/null
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| @@ -1,160 +0,0 @@
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| -# Copyright 2012 Google Inc. All Rights Reserved.
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| -#
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| -# Licensed under the Apache License, Version 2.0 (the "License");
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| -# you may not use this file except in compliance with the License.
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| -# You may obtain a copy of the License at
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| -#
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| -# http://www.apache.org/licenses/LICENSE-2.0
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| -#
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| -# Unless required by applicable law or agreed to in writing, software
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| -# distributed under the License is distributed on an "AS IS" BASIS,
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| -# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| -# See the License for the specific language governing permissions and
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| -# limitations under the License.
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| -
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| -from gslib.help_provider import HELP_NAME
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| -from gslib.help_provider import HELP_NAME_ALIASES
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| -from gslib.help_provider import HELP_ONE_LINE_SUMMARY
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| -from gslib.help_provider import HelpProvider
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| -from gslib.help_provider import HELP_TEXT
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| -from gslib.help_provider import HelpType
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| -from gslib.help_provider import HELP_TYPE
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| -
|
| -_detailed_help_text = ("""
|
| -<B>OVERVIEW</B>
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| - If you use gsutil in large production tasks (such as uploading or
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| - downloading many GB of data each night), there are a number of things
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| - you can do to help ensure success. Specifically, this section discusses
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| - how to script large production tasks around gsutil's resumable transfer
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| - mechanism.
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| -
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| -
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| -<B>BACKGROUND ON RESUMABLE TRANSFERS</B>
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| - First, it's helpful to understand gsutil's resumable transfer mechanism,
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| - and how your script needs to be implemented around this mechanism to work
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| - reliably. gsutil uses the resumable transfer support in the boto library
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| - when you attempt to upload or download a file larger than a configurable
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| - threshold (by default, this threshold is 1MB). When a transfer fails
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| - partway through (e.g., because of an intermittent network problem),
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| - boto uses a randomized binary exponential backoff-and-retry strategy:
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| - wait a random period between [0..1] seconds and retry; if that fails,
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| - wait a random period between [0..2] seconds and retry; and if that
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| - fails, wait a random period between [0..4] seconds, and so on, up to a
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| - configurable number of times (the default is 6 times). Thus, the retry
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| - actually spans a randomized period up to 1+2+4+8+16+32=63 seconds.
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| -
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| - If the transfer fails each of these attempts with no intervening
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| - progress, gsutil gives up on the transfer, but keeps a "tracker" file
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| - for it in a configurable location (the default location is ~/.gsutil/,
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| - in a file named by a combination of the SHA1 hash of the name of the
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| - bucket and object being transferred and the last 16 characters of the
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| - file name). When transfers fail in this fashion, you can rerun gsutil
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| - at some later time (e.g., after the networking problem has been
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| - resolved), and the resumable transfer picks up where it left off.
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| -
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| -
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| -<B>SCRIPTING DATA TRANSFER TASKS</B>
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| - To script large production data transfer tasks around this mechanism,
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| - you can implement a script that runs periodically, determines which file
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| - transfers have not yet succeeded, and runs gsutil to copy them. Below,
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| - we offer a number of suggestions about how this type of scripting should
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| - be implemented:
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| -
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| - 1. When resumable transfers fail without any progress 6 times in a row
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| - over the course of up to 63 seconds, it probably won't work to simply
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| - retry the transfer immediately. A more successful strategy would be to
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| - have a cron job that runs every 30 minutes, determines which transfers
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| - need to be run, and runs them. If the network experiences intermittent
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| - problems, the script picks up where it left off and will eventually
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| - succeed (once the network problem has been resolved).
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| -
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| - 2. If your business depends on timely data transfer, you should consider
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| - implementing some network monitoring. For example, you can implement
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| - a task that attempts a small download every few minutes and raises an
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| - alert if the attempt fails for several attempts in a row (or more or less
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| - frequently depending on your requirements), so that your IT staff can
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| - investigate problems promptly. As usual with monitoring implementations,
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| - you should experiment with the alerting thresholds, to avoid false
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| - positive alerts that cause your staff to begin ignoring the alerts.
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| -
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| - 3. There are a variety of ways you can determine what files remain to be
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| - transferred. We recommend that you avoid attempting to get a complete
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| - listing of a bucket containing many objects (e.g., tens of thousands
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| - or more). One strategy is to structure your object names in a way that
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| - represents your transfer process, and use gsutil prefix wildcards to
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| - request partial bucket listings. For example, if your periodic process
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| - involves downloading the current day's objects, you could name objects
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| - using a year-month-day-object-ID format and then find today's objects by
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| - using a command like gsutil ls gs://bucket/2011-09-27-*. Note that it
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| - is more efficient to have a non-wildcard prefix like this than to use
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| - something like gsutil ls gs://bucket/*-2011-09-27. The latter command
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| - actually requests a complete bucket listing and then filters in gsutil,
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| - while the former asks Google Storage to return the subset of objects
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| - whose names start with everything up to the *.
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| -
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| - For data uploads, another technique would be to move local files from a "to
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| - be processed" area to a "done" area as your script successfully copies files
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| - to the cloud. You can do this in parallel batches by using a command like:
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| -
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| - gsutil -m cp -R to_upload/subdir_$i gs://bucket/subdir_$i
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| -
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| - where i is a shell loop variable. Make sure to check the shell $status
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| - variable is 0 after each gsutil cp command, to detect if some of the copies
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| - failed, and rerun the affected copies.
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| -
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| - With this strategy, the file system keeps track of all remaining work to
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| - be done.
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| -
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| - 4. If you have really large numbers of objects in a single bucket
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| - (say hundreds of thousands or more), you should consider tracking your
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| - objects in a database instead of using bucket listings to enumerate
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| - the objects. For example this database could track the state of your
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| - downloads, so you can determine what objects need to be downloaded by
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| - your periodic download script by querying the database locally instead
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| - of performing a bucket listing.
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| -
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| - 5. Make sure you don't delete partially downloaded files after a transfer
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| - fails: gsutil picks up where it left off (and performs an MD5 check of
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| - the final downloaded content to ensure data integrity), so deleting
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| - partially transferred files will cause you to lose progress and make
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| - more wasteful use of your network. You should also make sure whatever
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| - process is waiting to consume the downloaded data doesn't get pointed
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| - at the partially downloaded files. One way to do this is to download
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| - into a staging directory and then move successfully downloaded files to
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| - a directory where consumer processes will read them.
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| -
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| - 6. If you have a fast network connection, you can speed up the transfer of
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| - large numbers of files by using the gsutil -m (multi-threading /
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| - multi-processing) option. Be aware, however, that gsutil doesn't attempt to
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| - keep track of which files were downloaded successfully in cases where some
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| - files failed to download. For example, if you use multi-threaded transfers
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| - to download 100 files and 3 failed to download, it is up to your scripting
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| - process to determine which transfers didn't succeed, and retry them. A
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| - periodic check-and-run approach like outlined earlier would handle this case.
|
| -
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| - If you use parallel transfers (gsutil -m) you might want to experiment with
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| - the number of threads being used (via the parallel_thread_count setting
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| - in the .boto config file). By default, gsutil uses 24 threads. Depending
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| - on your network speed, available memory, CPU load, and other conditions,
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| - this may or may not be optimal. Try experimenting with higher or lower
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| - numbers of threads, to find the best number of threads for your environment.
|
| -""")
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| -
|
| -
|
| -class CommandOptions(HelpProvider):
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| - """Additional help about using gsutil for production tasks."""
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| -
|
| - help_spec = {
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| - # Name of command or auxiliary help info for which this help applies.
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| - HELP_NAME : 'prod',
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| - # List of help name aliases.
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| - HELP_NAME_ALIASES : ['production', 'resumable', 'resumable upload',
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| - 'resumable transfer', 'resumable download',
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| - 'scripts', 'scripting'],
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| - # Type of help:
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| - HELP_TYPE : HelpType.ADDITIONAL_HELP,
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| - # One line summary of this help.
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| - HELP_ONE_LINE_SUMMARY : 'Scripting production data transfers with gsutil',
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| - # The full help text.
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| - HELP_TEXT : _detailed_help_text,
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| - }
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|
|