Add option to allow for unique object names across drivers

[agama]

In some situations, ensuring that the object names generated by drivers are guaranteed to be unique is a requirement. It would be nice to have an option supplied via the XML that would enable this feature, or to have a substitution string as a part of the object name prefix that would be recognised and replaced with the driver ID (e.g. obj_%d, where %d would be replaced).

[gilmcgrath]

adding null comment so I can track as a participant

[ywang19]

A good requirement, however, quick evaluation shows some conflicts with current code, we will do a deeper evaluation to see if and how to cover it.

thanks.
-Y.G.

[ywang19]

The division strategy should help on it, below part is from latest user guide section 4.10.2, let me know if it's you are asking for.

Division strategies are used to divide a work into multiple non-overlapping partitions which have smaller ranges of containers or objects, there strategies are supported: container (based), object (based), or none.
Different stage type has different default division strategy, for init/dispose, the default is “container”, for prepare/cleanup, the default is “object”, and for normal, the default is “none”.

We will use one example to explain the difference between different division strategies, here is a work as following:

If "division=container", it means the data range will be partitioned by container, the access pattern looks like:
Worker Container Range Object Range
#1 1-2 1-1000
#2 3-4 1-1000
#3 5-6 1-1000
#4 7-8 1-1000
(Note: it's not supported if # of workers is larger than # of containers.)

If "division=object", it means the data range will be partitioned by object, the access pattern looks like:
Worker Container Range Object Range
#1 1-8 1-250
#2 1-8 251-500
#3 1-8 501-750
#4 1-8 751-1000
(Note: it's not supported if the # of workers is larger than the # of objects.)

If "division=none", it is used to turn off division so that each worker does exactly what the work has specified—there is no partitions of the work, so each worker may touch all containers or objects.

[ywang19]

Assuming division strategy could cover this requirement well.

[EricJLarson]

Hi @ywang19,

In our tests, the "division" property prevents container-object names from being reused, but only in smaller workloads with < 4 drivers. In our tests using 17 drivers, the following causes workload configuration causes the creation of between 5 and 11 objects with a container-object name that was already created during the workload.

<work name="main" division="container" workers="17" totalOps="800">
...... containers=r(1,35);objects=u(1,900)... />

Are we mis-using the "division" field?
Could you provide a sample workload that will not have overwrites, but will have 17 workers and 800 writes?

Btw, we are a fan of your work!

Thank you,
Eric