- the file specified in the -c command line option
- the file at DEFAULT_CONF_FILE_LOCATION in env_default.h
Global Configuration Variables
port: assigned to variable “port”
- which port the scribe server will listen on
- default 0, passed at command line with -p, can also be set in conf file
max_msg_per_second:
- used in scribeHandler::throttleDeny
- default 0
- the default value is 0 and this parameter is ignored if the value is 0. With recent changes this parameter has become less relevant, and max_queue_size should be the parameter used for throttling bussiness
max_queue_size: in bytes
- used in scribeHandler::Log
- default 5,000,000 bytes
check_interval: in seconds
- used to control how often to check each store
- default 5
new_thread_per_category: yes/no
- If yes, will create a new thread for every category seen. Otherwise, will only create a single thread for every store defined in the configuration.
- For prefix stores or the default store, setting this parameter to “no” will cause all messages that match this category to get processed by a single store. Otherwise, a new store will be created for each unique category name.
- default yes
num_thrift_server_threads:
- Number of threads listening for incoming messages
- default 3
Example:
port=1463
max_msg_per_second=2000000
max_queue_size=10000000
check_interval=3Store Configuration
Scribe Server determines how to log messages based on the Stores defined in the configuration. Every store must specify what message category it handles with three exceptions:
default store: The ‘default’ category handles any category that is not handled by any other store. There can only be one default store.
prefix stores: If the specified category ends in a *, the store will handle all categories that begin with the specified prefix.
multiple categories: Can use ‘categories=’ to create multiple stores with a single store definition.
- categories=rock paper* scissors
In the above three cases, Scribe will create a subdirectory for each unique category in File Stores (unless new_thread_per_category is set to false).
Store Configuration Variables
category: Determines which messages are handled by this store
type:
- file
- buffer
- network
- bucket
- thriftfile
- null
- multi
target_write_size: 16,384 bytes by default
- determines how large to let the message queue grow for a given category before processing the messages
max_batch_size: 1,024,000 bytes by default (may not be in open-source yet)
- determines the amount of data from the in-memory store queue to be handled at a time. In practice, this (together with buffer file rotation size) controls how big a thrift call can be.
max_write_interval: 10 seconds by default
- determines how long to let the messages queue for a given category before processing the messages
must_succeed: yes/no
- Whether to requeue messages and retry if a store failed to process messages.
- If set to ‘no’, messages will be dropped if the store cannot process them.
- Note: We recommended using Buffer Stores to specify a secondary store to handle logging failures.
- default yes
Example:
category=statistics
type=file
target_write_size=20480
max_write_interval=2
File Store Configuration
File Stores write messages to a file.
file_path: defaults to “/tmp”
base_filename: defaults to category name
use_hostname_sub_directory: yes/no, default no
- Create a subdirectory using the server’s hostname
sub_directory: string
- Create a subdirectory with the specified name
rotate_period: “hourly”, “daily”, “never”, or number[suffix]; “never” by default
- determines how often to create new files
- suffix may be “s”, “m”, “h”, “d”, “w” for seconds (the default), minutes, hours, days and weeks, respectively
rotate_hour: 0-23, 1 by default
- if rotation_period is daily, determines what hour of day to rotate
rotate_minute 0-59, 15 by default
- if rotation_period is daily or hourly, determines how many minutes after the hour to rotate
max_size: 1,000,000,000 bytes by default
- determines approximately how large to let a file grow before rotating to a new file
write_meta: “yes” or anything else; false by default
- if the file was rotated, the last line will contain "scribe_meta: " followed by the next filename
fs_type: supports two types “std” and “hdfs”. “std” by default
chunk_size: 0 by default. If a chunk size is specified, no messages within the file will cross chunk boundaries unless there are messages larger than the chunk size
add_newlines: 0 or 1, 0 by default
- if set to 1, will write a newline after every message
create_symlink: “yes” or anything else; “yes” by default
- if true, will maintain a symlink that points to the most recently written file
write_stats: yes/no, yes by default
- whether to create a scribe_stats file for each store to keep track of files written
max_write_size: 1000000 bytes by default. The file store will try to flush the data out to the file system in chunks of max_write_size of bytes. max_write_size cannot be more than max_size. Say due to target_write_size a certain number of messages were buffered. And then the file store was called to save these messages. The file-store will save these messages at least max_write_size bytes sized chunks at a time. The last write that the file store will make can be smaller than max_write_size.
Example:
category=sprockets
type=file
file_path=/tmp/sprockets
base_filename=sprockets_log
max_size=1000000
add_newlines=1
rotate_period=daily
rotate_hour=0
rotate_minute=10
max_write_size=4096
Network Store Configuration
Network Stores forward messages to other Scribe Servers. Scribe keeps persistent connections open as long as it is able to send messages. (It will only re-open a connection on error or if the downstream machine is overloaded). Scribe will send messages in batches during normal operation based on how many messages are currently sitting in the queue waiting to be sent. (If Scribe is backed up and buffering messages to local disk, Scribe will send messages in chunks based on the buffer file sizes.)
remote_host: name or ip of remote host to forward messages
remote_port: port number on remote host
timeout: socket timeout, in MS; defaults to DEFAULT_SOCKET_TIMEOUT_MS, which is set to 5000 in store.h
use_conn_pool: “yes” or anything else; defaults to false
- whether to use connection pooling instead of opening up multiple connections to each remote host
Example:
category=default
type=network
remote_host=hal
remote_port=1465
Buffer Store Configuration
Buffer Stores must have two sub-stores named “primary” and “secondary”. Buffer Stores will first attempt to Log messages to the primary store and only log to the secondary if the primary is not available. Once the primary store comes back online, a Buffer store will read messages out of the secondary store and send them to the primary store (unless replay_buffer=no). Only stores that are readable (store that implement the readOldest() method) may be used as secondary store. Currently, the only readable stores are File Stores and Null Stores.
max_queue_length: 2,000,000 messages by default
- if the number of messages in the queue exceeds this value, the buffer store will switch to writing to the secondary store
buffer_send_rate: 1 by default
- determines, for each check_interval, how many times to read a group of messages from the secondary store and send them to the primary store
retry_interval: 300 seconds by default
- how long to wait to retry sending to the primary store after failing to write to the primary store
retry_interval_range: 60 seconds by default
- will randomly pick a retry interval that is within this range of the specified retry_interval
replay_buffer: yes/no, default yes
- If set to ‘no’, Buffer Store will not remove messages from the secondary store and send them to the primary store
Example:
category=default
type=buffer
buffer_send_rate=1
retry_interval=30
retry_interval_range=10
type=network
remote_host=wopr
remote_port=1456
type=file
file_path=/tmp
base_filename=thisisoverwritten
max_size=10000000
Bucket Store Configuration
Bucket Stores will hash messages to multiple files using a prefix of each message as the key.
You can define each bucket implicitly(using a single ‘bucket’ definition) or explicitly (using a bucket definition for every bucket). Bucket Stores that are defined implicitly must have a substore named “bucket” that is either a File Store, Network store or ThriftFile Store (see examples).
num_buckets: defaults to 1
- number of buckets to hash into
- messages that cannot be hashed into any bucket will be put into a special bucket number 0
bucket_type: “key_hash”, “key_modulo”, or “random”
delimiter: must be an ascii code between 1 and 255; otherwise the default delimiter is ‘:’
- The message prefix up to(but not including) the first occurrence of the delimiter will be used as the key to do the hash/modulo. ‘random’ hashing does not use a delimiter.
remove_key: yes/no, defaults to no
- whether to remove the key prefix from each message.
bucket_subdir: the name of each subdirectory will be this name followed by the bucket number if a single ‘bucket’ definition is used
Example:
category=bucket_me
type=bucket
num_buckets=5
bucket_subdir=bucket
bucket_type=key_hash
delimiter=58
type=file
fs_type=std
file_path=/tmp/scribetest
base_filename=bucket_me
Instead of using a single ‘bucket’ definition for all buckets, you can specify each bucket explicitly:
category=bucket_me
type=bucket
num_buckets=2
bucket_type=key_hash
type=file
fs_type=std
file_path=/tmp/scribetest/bucket0
base_filename=bucket0
...
...
You can also bucket into network stores as well:
category=bucket_me
type=bucket
num_buckets=2
bucket_type=random
type=file
fs_type=std
file_path=/tmp/scribetest/bucket0
base_filename=bucket0
type=network
remote_host=wopr
remote_port=1463
type=network
remote_host=hal
remote_port=1463
Null Store Configuration
Null Stores can be used to tell Scribe to ignore all messages of a given category.
(no configuration parameters)
Example:
category=tps_report*
type=null
Multi Store Configuration
A Multi Store is a store that will forward all messages to multiple sub-stores.
A Multi Store may have any number of substores named “store0”, “store1”, “store2”, etc
report_success: “all” or “any”, defaults to “all”
- whether all substores or any substores must succeed in logging a message in order for the Multi Store to report the message logging as successful
Example:
category=default
type=multi
target_write_size=20480
max_write_interval=1
type=file
file_path=/tmp/store0
type=file
file_path=/tmp/store1
Thriftfile Store Configuration
A Thriftfile store is similar to a File store except that it stores messages in a Thrift TFileTransport file.
file_path: defaults to “/tmp”
base_filename: defaults to category name
rotate_period: “hourly”, “daily”, “never”, or number[suffix]; “never” by default
- determines how often to create new files
- suffix may be “s”, “m”, “h”, “d”, “w” for seconds (the default), minutes, hours, days and weeks, respectively
rotate_hour: 0-23, 1 by default
- if rotation_period is daily, determines what hour of day to rotate
rotate_minute 0-59, 15 by default
- if rotation_period is daily or hourly, determines how many minutes after the hour to rotate
max_size: 1,000,000,000 bytes by default
- determines approximately how large to let a file grow before rotating to a new file
fs_type: currently only “std” is supported; “std” by default
chunk_size: 0 by default
- if a chunk size is specified, no messages within the file will cross chunk boundaries unless there are messages larger than the chunk size
create_symlink: “yes” or anything else; “yes” by default
- if true, will maintain a symlink that points to the most recently written file
flush_frequency_ms: milliseconds, will use TFileTransport default of 3000ms if not specified
- determines how frequently to sync the Thrift file to disk
msg_buffer_size: in bytes, will use TFileTransport default of 0 if not specified
- if non-zero, store will reject any writes larger than this size
Example:
category=sprockets
type=thriftfile
file_path=/tmp/sprockets
base_filename=sprockets_log
max_size=1000000
flush_frequency_ms=2000
