How to get the current index and total runs in a multirun?

[kunaltyagi]

If I start a run with python main.py -m +x="range(0,3)", I wish to get that there are 3 runs in total, with the current run being i (in {1,2,3} or {0,1,2}: doesn't matter).

I don't see any documentation for this. Is this possible? If not, how can this be achieved?

[odelalleau]

It may be in HydraConfig (not 100% sure), you can inspect it with:

from hydra.core.hydra_config import HydraConfig
from omegaconf import OmegaConf

hydra_cfg = HydraConfig.get()
print(OmegaConf.to_yaml(hydra_cfg))

[odelalleau]

For the current index and total number of runs since that's what you asked for :p
(again I'm not sure it's there, it's just a guess)

[kunaltyagi]

hydra.job.num and hydra.job.id both give the current index, but not the total number of runs

[Jasha10]

@kunaltyagi I don't believe that the total number of runs is calculated ahead of time or stored in the hydra config.
For exmaple, take a look at the file hydra/_internal/core_plugins/basic_sweeper.py from the hydra source code. You will see that there is a loop of the form

while not self.is_done():
    batch = self.get_job_batch()
    ...
    results = self.launcher.launch(batch, initial_job_idx=initial_job_idx)
    ...
    returns.append(results)

This while loop does not keep track of how many jobs have been run. You could potentially create a custom launcher or custom sweeper (based on the basic_launcher or the basic_sweeper) to calculate the total number of jobs that will be run before starting the loop.

[kunaltyagi]

I see that we have the length ready in

hydra/hydra/_internal/core_plugins/basic_sweeper.py

Line 158 in 809718c

self.overrides = self.split_arguments(overrides, self.max_batch_size)

(just need to use len)

It seems a potential PR to enable this in basic sweeper is possible.How do I supply that to hydra conf?

[kunaltyagi]

Any idea @Jasha10 ?

[lukaslobmaier]

A simple solution for hydra v1.2:

The value is stored in the hydra config:
#1 Hydra config
config=hydra.core.hydra_config.HydraConfig.get()
#2 Acces MultirunType
run_type=hydra.core.hydra_config.HydraConfig.get().mode
#3 Total num of runs
total_num=hydra.core.hydra_config.HydraConfig.get().mode.value
#4 Current num of job (only defined for multi runs)
current_num=hydra.core.hydra_config.HydraConfig.get().job.id