Roll version of gsutil to 4.15.

third_party/gsutil/gslib/addlhelp/prod.py

 # -*- coding: utf-8 -*-
 # Copyright 2012 Google Inc. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
@@ skipping 17 matching lines @@
 
 
 <B>BACKGROUND ON RESUMABLE TRANSFERS</B>
   First, it's helpful to understand gsutil's resumable transfer mechanism,
   and how your script needs to be implemented around this mechanism to work
   reliably. gsutil uses resumable transfer support when you attempt to upload
   or download a file larger than a configurable threshold (by default, this
   threshold is 2 MiB). When a transfer fails partway through (e.g., because of
   an intermittent network problem), gsutil uses a truncated randomized binary
   exponential backoff-and-retry strategy that by default will retry transfers up
-  to 6 times over a 63 second period of time (see "gsutil help retries" for
+  to 23 times over a 10 minute period of time (see "gsutil help retries" for
   details). If the transfer fails each of these attempts with no intervening
   progress, gsutil gives up on the transfer, but keeps a "tracker" file for
   it in a configurable location (the default location is ~/.gsutil/, in a file
   named by a combination of the SHA1 hash of the name of the bucket and object
   being transferred and the last 16 characters of the file name). When transfers
   fail in this fashion, you can rerun gsutil at some later time (e.g., after
   the networking problem has been resolved), and the resumable transfer picks
   up where it left off.
 
 
 <B>SCRIPTING DATA TRANSFER TASKS</B>
   To script large production data transfer tasks around this mechanism,
   you can implement a script that runs periodically, determines which file
   transfers have not yet succeeded, and runs gsutil to copy them. Below,
   we offer a number of suggestions about how this type of scripting should
   be implemented:
 
-  1. When resumable transfers fail without any progress 6 times in a row
-     over the course of up to 63 seconds, it probably won't work to simply
+  1. When resumable transfers fail without any progress 23 times in a row
+     over the course of up to 10 minutes, it probably won't work to simply
      retry the transfer immediately. A more successful strategy would be to
      have a cron job that runs every 30 minutes, determines which transfers
      need to be run, and runs them. If the network experiences intermittent
      problems, the script picks up where it left off and will eventually
      succeed (once the network problem has been resolved).
 
   2. If your business depends on timely data transfer, you should consider
      implementing some network monitoring. For example, you can implement
      a task that attempts a small download every few minutes and raises an
      alert if the attempt fails for several attempts in a row (or more or less
@@ skipping 32 matching lines @@
      be done.
 
   4. If you have really large numbers of objects in a single bucket
      (say hundreds of thousands or more), you should consider tracking your
      objects in a database instead of using bucket listings to enumerate
      the objects. For example this database could track the state of your
      downloads, so you can determine what objects need to be downloaded by
      your periodic download script by querying the database locally instead
      of performing a bucket listing.
 
-  5. Make sure you don't delete partially downloaded files after a transfer
-     fails: gsutil picks up where it left off (and performs an MD5 check of
-     the final downloaded content to ensure data integrity), so deleting
+  5. Make sure you don't delete partially downloaded temporary files after a
+     transfer fails: gsutil picks up where it left off (and performs a hash
+     of the final downloaded content to ensure data integrity), so deleting
      partially transferred files will cause you to lose progress and make
-     more wasteful use of your network. You should also make sure whatever
-     process is waiting to consume the downloaded data doesn't get pointed
-     at the partially downloaded files. One way to do this is to download
-     into a staging directory and then move successfully downloaded files to
-     a directory where consumer processes will read them.
+     more wasteful use of your network.
 
   6. If you have a fast network connection, you can speed up the transfer of
      large numbers of files by using the gsutil -m (multi-threading /
      multi-processing) option. Be aware, however, that gsutil doesn't attempt to
      keep track of which files were downloaded successfully in cases where some
      files failed to download. For example, if you use multi-threaded transfers
      to download 100 files and 3 failed to download, it is up to your scripting
      process to determine which transfers didn't succeed, and retry them. A
      periodic check-and-run approach like outlined earlier would handle this
      case.
 
      If you use parallel transfers (gsutil -m) you might want to experiment with
      the number of threads being used (via the parallel_thread_count setting
      in the .boto config file). By default, gsutil uses 10 threads for Linux
      and 24 threads for other operating systems. Depending on your network
      speed, available memory, CPU load, and other conditions, this may or may
      not be optimal. Try experimenting with higher or lower numbers of threads
      to find the best number of threads for your environment.
-
-<B>RUNNING GSUTIL ON MULTIPLE MACHINES</B>
-  When running gsutil on multiple machines that are all attempting to use the
-  same OAuth2 refresh token, it is possible to encounter rate limiting errors
-  for the refresh requests (especially if all of these machines are likely to
-  start running gsutil at the same time). To account for this, gsutil will
-  automatically retry OAuth2 refresh requests with a truncated randomized
-  exponential backoff strategy like that which is described in the
-  "BACKGROUND ON RESUMABLE TRANSFERS" section above. The number of retries
-  attempted for OAuth2 refresh requests can be controlled via the
-  "oauth2_refresh_retries" variable in the .boto config file.
 """)
 
 
 class CommandOptions(HelpProvider):
   """Additional help about using gsutil for production tasks."""
 
   # Help specification. See help_provider.py for documentation.
   help_spec = HelpProvider.HelpSpec(
       help_name='prod',
       help_name_aliases=[
           'production', 'resumable', 'resumable upload', 'resumable transfer',
           'resumable download', 'scripts', 'scripting'],
       help_type='additional_help',
       help_one_line_summary='Scripting Production Transfers',
       help_text=_DETAILED_HELP_TEXT,
       subcommand_help_text={},
   )