Index: tools/telemetry/third_party/gsutil/gslib/addlhelp/prod.py |
diff --git a/tools/telemetry/third_party/gsutil/gslib/addlhelp/prod.py b/tools/telemetry/third_party/gsutil/gslib/addlhelp/prod.py |
deleted file mode 100644 |
index df090145d03a23b5a4a6f4d472031b5151637c6a..0000000000000000000000000000000000000000 |
--- a/tools/telemetry/third_party/gsutil/gslib/addlhelp/prod.py |
+++ /dev/null |
@@ -1,164 +0,0 @@ |
-# -*- 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 |
-# distributed under the License is distributed on an "AS IS" BASIS, |
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
-# See the License for the specific language governing permissions and |
-# limitations under the License. |
-"""Additional help about using gsutil for production tasks.""" |
- |
-from __future__ import absolute_import |
- |
-from gslib.help_provider import HelpProvider |
- |
-_DETAILED_HELP_TEXT = (""" |
-<B>OVERVIEW</B> |
- If you use gsutil in large production tasks (such as uploading or |
- downloading many GiBs of data each night), there are a number of things |
- you can do to help ensure success. Specifically, this section discusses |
- how to script large production tasks around gsutil's resumable transfer |
- mechanism. |
- |
- |
-<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 |
- 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 |
- 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 |
- frequently depending on your requirements), so that your IT staff can |
- investigate problems promptly. As usual with monitoring implementations, |
- you should experiment with the alerting thresholds, to avoid false |
- positive alerts that cause your staff to begin ignoring the alerts. |
- |
- 3. There are a variety of ways you can determine what files remain to be |
- transferred. We recommend that you avoid attempting to get a complete |
- listing of a bucket containing many objects (e.g., tens of thousands |
- or more). One strategy is to structure your object names in a way that |
- represents your transfer process, and use gsutil prefix wildcards to |
- request partial bucket listings. For example, if your periodic process |
- involves downloading the current day's objects, you could name objects |
- using a year-month-day-object-ID format and then find today's objects by |
- using a command like gsutil ls "gs://bucket/2011-09-27-*". Note that it |
- is more efficient to have a non-wildcard prefix like this than to use |
- something like gsutil ls "gs://bucket/*-2011-09-27". The latter command |
- actually requests a complete bucket listing and then filters in gsutil, |
- while the former asks Google Storage to return the subset of objects |
- whose names start with everything up to the "*". |
- |
- For data uploads, another technique would be to move local files from a "to |
- be processed" area to a "done" area as your script successfully copies |
- files to the cloud. You can do this in parallel batches by using a command |
- like: |
- |
- gsutil -m cp -r to_upload/subdir_$i gs://bucket/subdir_$i |
- |
- where i is a shell loop variable. Make sure to check the shell $status |
- variable is 0 after each gsutil cp command, to detect if some of the copies |
- failed, and rerun the affected copies. |
- |
- With this strategy, the file system keeps track of all remaining work to |
- 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 |
- 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. |
- |
- 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={}, |
- ) |