GEO Balancer

The geo balancer uses the Converter mechanism to redistribute files according to their geographical location. Currently it is only moving files with replica layouts. To avoid oscillations a threshold parameter defines when geo balancing stops e.g. the deviation from the average in a group is less then the threshold parameter.

Configuration

GEO balancing uses the relative filling state of a geo tag and not absolute byte values.

GEO balancing is enabled/disabled by space:

# enable
eos space config default space.geobalancer=on
# disable
eos space config default space.geobalancer=off

The curent status of GEO Balancing can be seen via

eos -b space status default
# ------------------------------------------------------------------------------------
# Space Variables
# ....................................................................................
...
geobalancer                    := off
geobalancer.ntx                := 0
geobalancer.threshold          := 0.1
...

The number of concurrent transfers to schedule is defined via the geobalancer.ntx space variable:

# schedule 10 transfers in parallel
eos space config default space.geobalancer.ntx=10

The threshold in percent is defined via the geobalancer.threshold variable:

# set a 5 percent threshold
eos space config default space.geobalancer.threshold=5

Make sure that you have enabled the converter and the converter.ntx space variable is bigger than geobalancer.ntx :

# enable the converter
eos space config default space.converter=on
# run 20 conversion transfers in parallel
eos space config default space.converter.ntx=20

One can see the same settings and the number of active conversion transfers (scroll to the right):

eos space ls
#------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
#     type #           name #  groupsize #   groupmod #N(fs) #N(fs-rw) #sum(usedbytes) #sum(capacity) #capacity(rw) #nom.capacity #quota #balancing # threshold # converter #  ntx # active #intergroup
#------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
spaceview           default           22           22    202       123          2.91 T       339.38 T      245.53 T          0.00     on        off        0.00          on 100.00     0.00         off

Warning

You have to configure geo mapping for clients, atleast for the MGM machine, otherwise EOS does not apply the geoplacement/scheduling algorithm and GEO Balancing does not give the expected results!

Log Files

The GEO Balancer has a dedicated log file under /var/log/eos/mgm/GeoBalancer.log which shows basic variables used for balancing decisions and scheduled transfers. To get more verbose information you can change the log level:

# switch to debug log level on the MGM
eos debug debug

# switch back to info log level on the MGM
eos debug info