Space watcher is a background process that checks the amount of free space in the
database and gives warning when space is running low.
Space Watcher
Functionality
Once a minute, space watcher runs a ls or
dir command, then writes the free space in bytes to a table named
aspera_db_disk_space_free. The exact command it executes is:
df -k -P "aspera_console_db_directory_path"
It only writes one record, always with "id=1". The aspera_db_disk_space_free table will
never have more than one record in it. This table only has three fields:
| Field |
Value |
| id |
Always equal to 1. |
| bytes_free |
BIGINT, max value = 9223372036854775807, which is approximately 8191
petabytes |
| last_reported_at |
The time space watcher last stored an entry in the table. |
If the process fails to figure out free space for any reason or fails to
connect to MySQL, it does nothing and logs nothing. Successful or not, it then closes its
connection and then sleeps for a minute before repeating the process.
Space Watcher Messages in Console
Unless warnings have been disabled (by
setting the warning threshold to zero), Console checks the aspera_db_disk_space_free
table when rendering a page. If it sees that there are no records in the table, or that it has
been longer than 10 minutes since space watcher last reported, Console displays the following
message at the top of the page: "WARNING: No recent data from database free space
watcher". If the last entry is recent (within 10 minutes) but the number of free bytes
is less than the configured warning level (default: 10 gigabytes), it shows a message such as
the following: "WARNING: Database free space low (7.5 GB remaining)".