Software Utilities

httpmsgbus

Description

httpmsgbus is a server implementing the HMB protocol. It can use a database (-D) or RAM only. httpmsgbus usually runs behind a web server acting as a reverse proxy.

Database URL

Supported database types are mongodb and filedb. MongoDB is recommended in most scenarios. Filedb is suitable for binary messages with fixed size, such as waveform records. Database URL can take one of the following forms:

mongodb://server:port

Use MongoDB server running at server:port. A repository will be created for each bus and a capped collection for each queue. The collection size is determined by the -q command-line parameter.

filedb:///directory?blocksPerFile=int&blocksize=int&bufsize=int&maxOpenFiles=int

Use filedb in directory. A subdirectory will be created for each bus and a further subdirectory for each queue. Messages will be stored in (possibly sparse) files consisting of fixed size blocks. File name will be the sequence number of the first block in file. The total size of files in a directory is determined by the -q command-line parameter.

The following optional parameters are supported by filedb:

blocksPerFile (default 1024)

Number of blocks per file.

blocksize (default 1024)

Size of one block in bytes, maximum message size.

bufsize (default 65536)

Read buffer size.

maxOpenFiles (default 800)

Maximum number of file handles to keep open.

X-Forwarded-For

When HMB runs behind a reverse proxy, connections appear to originate from localhost or wherever the proxy is running. Using the X-Forwarded-For HTTP header, it is possible to determine the actual IP address of a client, which is then used for session counting (-c), etc.

Sequence difference into future

When using multiple servers, it may happen that a client requests a future message that has not reached the current server yet. Sequence numbers in future can be enabled with the -d command-line option. If the maximum difference is exceeded, the sequence number is considered invalid and the current seqence number is used.

Command-line

httpmsgbus [options]

-D string	Database URL
-F	Use X-Forwarded-For
-P int	TCP port (default 8000)
-V	Show program’s version and exit
-b int	Buffer (RAM) size in messages per queue (default 100)
-c int	Connections (sessions) per IP (default 10)
-d int	Maximum sequence difference into future (default 0)
-h	Show help message
-p int	Maximum size of POST data in KB (default 10240)
-q int	Queue (MongoDB capped collection) size in MB (default 256)
-s	Log via syslog
-t int	Session timeout in seconds (default 120)

hmbseedlink

Description

hmbseedlink is a proxy implementing the SeedLink protocol on top of HMB. A SeedLink station maps to an HMB queue and a SeedLink stream maps to an HMB topic. The payload of an HMB message would be a Mini-SEED record.

Command-line

hmbseedlink [options]

-H string	Source HMB URL
-O string	Organization
-P int	TCP port (default 18000)
-V	Show program’s version and exit
-c int	Connections per IP (default 10)
-h	Show help message
-q int	Limit backlog of records (queue length)
-s	Log via syslog
-t int	HMB timeout in seconds (default 120)
-w int	Wait for out-of-order data in seconds

wavefeed

Description

wavefeed is a program that runs a SeedLink plugin (normally chain_plugin) and sends the waveform data to HMB. Only log and Mini-SEED packets are supported.

Command-line

wavefeed [options]

-C string	Plugin command line
-H string	Destination HMB URL
-V	Show program’s version and exit
-X string	Regex matching channels with unreliable timing
-b int	Maximum number of messages to buffer (default 1024)
-h	Show help message
-s	Log via syslog
-t int	HMB timeout in seconds (default 120)