| 156 |
156 |
how to generate these values for input to hbal would be to track "xm
|
| 157 |
157 |
list" for instance over a day and by computing the delta of the cpu
|
| 158 |
158 |
values, and feed that via the \fI-U\fR option for all instances (and
|
| 159 |
|
keep the other metrics as zero). For the algorithm to work, all that
|
| 160 |
|
is needed is that the values are consistent for a metric across all
|
|
159 |
keep the other metrics as one). For the algorithm to work, all that is
|
|
160 |
needed is that the values are consistent for a metric across all
|
| 161 |
161 |
instances (e.g. all instances use cpu% to report cpu usage, but they
|
| 162 |
|
could represent network bandwith in Gbps).
|
|
162 |
could represent network bandwith in Gbps). Note that it's recommended
|
|
163 |
to not have zero as the load value for any instance metric since then
|
|
164 |
secondary instances are not well balanced.
|
| 163 |
165 |
|
| 164 |
166 |
On a perfectly balanced cluster (all nodes the same size, all
|
| 165 |
|
instances the same size and spread across the nodes equally), all
|
| 166 |
|
values would be zero. This doesn't happen too often in practice :)
|
|
167 |
instances the same size and spread across the nodes equally), the
|
|
168 |
values for all metrics would be zero. This doesn't happen too often in
|
|
169 |
practice :)
|
| 167 |
170 |
|
| 168 |
171 |
.SS OFFLINE INSTANCES
|
| 169 |
172 |
|
| ... | ... | |
| 371 |
374 |
the instance name must match exactly the instance as read from
|
| 372 |
375 |
Ganeti. In case of unknown instance names, the program will abort.
|
| 373 |
376 |
|
| 374 |
|
If not given, the default values are zero for all metrics and thus
|
| 375 |
|
dynamic utilisation has no effect on the balancing algorithm.
|
|
377 |
If not given, the default values are one for all metrics and thus
|
|
378 |
dynamic utilisation has only one effect on the algorithm: the
|
|
379 |
equalisation of the secondary instances across nodes (this is the only
|
|
380 |
metric that is not tracked by another, dedicated value, and thus the
|
|
381 |
disk load of instances will cause secondary instance
|
|
382 |
equalisation). Note that value of one will also influence slightly the
|
|
383 |
primary instance count, but that is already tracked via other metrics
|
|
384 |
and thus the influence of the dynamic utilisation will be practically
|
|
385 |
insignificant.
|
| 376 |
386 |
|
| 377 |
387 |
.TP
|
| 378 |
388 |
.BI "-n" nodefile ", --nodes=" nodefile
|