Webhdfs output plugin
editWebhdfs output plugin
edit- Plugin version: v3.0.6
- Released on: 2018-04-06
- Changelog
For other versions, see the Versioned plugin docs.
Getting Help
editFor questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.
Dependencies
editThis plugin has no dependency on jars from hadoop, thus reducing configuration and compatibility problems. It uses the webhdfs gem from Kazuki Ohta and TAGOMORI Satoshi (@see: https://github.com/kzk/webhdfs). Optional dependencies are zlib and snappy gem if you use the compression functionality.
Operational Notes
editIf you get an error like:
Max write retries reached. Exception: initialize: name or service not known {:level=>:error}
make sure that the hostname of your namenode is resolvable on the host running Logstash. When creating/appending
to a file, webhdfs somtime sends a 307 TEMPORARY_REDIRECT
with the HOSTNAME
of the machine its running on.
Usage
editThis is an example of Logstash config:
input { ... } filter { ... } output { webhdfs { host => "127.0.0.1" # (required) port => 50070 # (optional, default: 50070) path => "/user/logstash/dt=%{+YYYY-MM-dd}/logstash-%{+HH}.log" # (required) user => "hue" # (required) } }
Webhdfs Output Configuration Options
editThis plugin supports the following configuration options plus the Common Options described later.
Setting | Input type | Required |
---|---|---|
string, one of |
No |
|
No |
||
Yes |
||
No |
||
No |
||
No |
||
Yes |
||
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
string, one of |
No |
|
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
Yes |
Also see Common Options for a list of options supported by all output plugins.
compression
edit-
Value can be any of:
none
,snappy
,gzip
-
Default value is
"none"
Compress output. One of [none, snappy, gzip]
flush_size
edit- Value type is number
-
Default value is
500
Sending data to webhdfs if event count is above, even if store_interval_in_secs
is not reached.
host
edit- This is a required setting.
- Value type is string
- There is no default value for this setting.
The server name for webhdfs/httpfs connections.
idle_flush_time
edit- Value type is number
-
Default value is
1
Sending data to webhdfs in x seconds intervals.
kerberos_keytab
edit- Value type is string
- There is no default value for this setting.
Set kerberos keytab file. Note that the gssapi library needs to be available to use this.
path
edit- This is a required setting.
- Value type is string
- There is no default value for this setting.
The path to the file to write to. Event fields can be used here,
as well as date fields in the joda time format, e.g.:
/user/logstash/dt=%{+YYYY-MM-dd}/%{@source_host}-%{+HH}.log
port
edit- Value type is number
-
Default value is
50070
The server port for webhdfs/httpfs connections.
retry_interval
edit- Value type is number
-
Default value is
0.5
How long should we wait between retries.
retry_known_errors
edit- Value type is boolean
-
Default value is
true
Retry some known webhdfs errors. These may be caused by race conditions when appending to same file, etc.
retry_times
edit- Value type is number
-
Default value is
5
How many times should we retry. If retry_times is exceeded, an error will be logged and the event will be discarded.
single_file_per_thread
edit- Value type is boolean
-
Default value is
false
Avoid appending to same file in multiple threads. This solves some problems with multiple logstash output threads and locked file leases in webhdfs. If this option is set to true, %{[@metadata][thread_id]} needs to be used in path config settting.
snappy_bufsize
edit- Value type is number
-
Default value is
32768
Set snappy chunksize. Only neccessary for stream format. Defaults to 32k. Max is 65536 @see http://code.google.com/p/snappy/source/browse/trunk/framing_format.txt
snappy_format
edit-
Value can be any of:
stream
,file
-
Default value is
"stream"
Set snappy format. One of "stream", "file". Set to stream to be hive compatible.
use_httpfs
edit- Value type is boolean
-
Default value is
false
Use httpfs mode if set to true, else webhdfs.
Common Options
editThe following configuration options are supported by all output plugins:
codec
edit- Value type is codec
-
Default value is
"line"
The codec used for output data. Output codecs are a convenient method for encoding your data before it leaves the output without needing a separate filter in your Logstash pipeline.
enable_metric
edit- Value type is boolean
-
Default value is
true
Disable or enable metric logging for this specific plugin instance. By default we record all the metrics we can, but you can disable metrics collection for a specific plugin.
id
edit- Value type is string
- There is no default value for this setting.
Add a unique ID
to the plugin configuration. If no ID is specified, Logstash will generate one.
It is strongly recommended to set this ID in your configuration. This is particularly useful
when you have two or more plugins of the same type. For example, if you have 2 webhdfs outputs.
Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.
output { webhdfs { id => "my_plugin_id" } }
Variable substitution in the id
field only supports environment variables
and does not support the use of values from the secret store.