MongoDB Output Plugin
out_mongo Buffered Output plugin writes records into MongoDB, the emerging document-oriented database system.
|If you're using ReplicaSet, please see the out_mongo_replset article instead.|
Table of Contents
- Why Fluentd with MongoDB?
- Example Configuration
- type (required)
- host (required)
- port (required)
- database (required)
- collection (required, if not tag_mapped)
- Buffer Parameters
- buffer_queue_limit, buffer_chunk_limit
- retry_wait, retry_limit and max_retry_wait
- Further Reading
Why Fluentd with MongoDB?
Fluentd enables your apps to insert records to MongoDB asynchronously with batch-insertion, unlike direct insertion of records from your apps. This has the following advantages:
- less impact on application performance
- higher MongoDB insertion throughput while maintaining JSON record structure
out_mongo is included in td-agent by default. Fluentd gem users will need to install the fluent-plugin-mongo gem using the following command.
$ fluent-gem install fluent-plugin-mongo
# Single MongoDB <match mongo.**> type mongo host fluentd port 27017 database fluentd collection test # for capped collection capped capped_size 1024m # authentication user michael password jordan # flush flush_interval 10s </match>
Please see the Store Apache Logs into MongoDB article for real-world use cases.
|Please see the Config File article for the basic structure and syntax of the configuration file.|
The value must be
The MongoDB hostname.
The MongoDB port.
The database name.
collection (required, if not tag_mapped)
The collection name.
This option enables capped collection. This is always recommended because MongoDB is not suited to storing large amounts of historical data.
Sets the capped collection size.
The username to use for authentication.
The password to use for authentication.
This option will allow out_mongo to use Fluentd’s tag to determine the destination collection. For example, if you generate records with tags ‘mongo.foo’, the records will be inserted into the
foo collection within the
<match mongo.*> type mongo host fluentd port 27017 database fluentd # Set 'tag_mapped' if you want to use tag mapped mode. tag_mapped # If the tag is "mongo.foo", then the prefix "mongo." is removed. # The inserted collection name is "foo". remove_tag_prefix mongo. # This configuration is used if the tag is not found. The default is 'untagged'. collection misc </match>
This option is useful for flexible log collection.
For advanced usage, you can tune Fluentd’s internal buffering mechanism with these parameters.
The length of the chunk queue and the size of each chunk, respectively. Please see the Buffer Plugin Overview article for the basic buffer structure. The default values are 64 and 8m, respectively. The suffixes “k” (KB), “m” (MB), and “g” (GB) can be used for buffer_chunk_limit.
The interval between data flushes. The default is 60s. The suffixes “s” (seconds), “m” (minutes), and “h” (hours) can be used.
retry_wait, retry_limit and max_retry_wait
The interval between write retries, and the number of retries. The default values are 1.0 and 17, respectively.
retry_wait doubles every retry (e.g. the last retry waits for 131072 sec, roughly 36 hours), and
max_retry_wait may be used to limit the maximum retry interval.
The number of threads to flush the buffer. This option can be used to parallelize writes into the output(s) designated by the output plugin. The default is 1.
log_level option (Fluentd v0.10.43 and above)
log_level option allows the user to set different levels of logging for each plugin. The supported log levels are:
Please see the logging article for further details.
If this article is incorrect or outdated, or omits critical information, please let us know.