Hi all,
I'm involved in a sizable GemFire Project right now that is requiring me to
execute Functions in a number of ways, and I wanted to poll the community
for some best practices. So initially I would execute all functions like
this.
ResultCollector<?, ?> rc = FunctionService.onRegion(region)
.withArgs(arguments).execute("my-awesome-function");
And this worked reliably for quite some time, until I started mixing
up functions that were executing on partition redundant data and
replicated data. I initially started having problems with this method
when I had this setup.
1 locator, 2 servers, and executing functions that would run queries
on partition redundant and replicated regions. I started getting this
problem where the function would execute on both servers, and the
result collector would indeterminately chose a server to return
results from. According to logging statements placed within my
function I was able to confirm that the function was being executed
twice, on both servers. We were able to fix this problem by switching
from executing on region, to executing on Pool. The initial logic
being since there was replicated data on both servers, the function
would execute on both servers(Hyptothesis).
Another issue was executing functions from within a function without a
function context. Let's say I have one function that I execute with
on Pool, there for it is passed a Function Context. But when I'm
actually in the function I need to execute other functions, some
needing a RegionFunctionContext and some just needing a
FunctionContext. Initially I was able to just use a Result Collector
and FunctionService.onRegion to get a region context, and then pass my
current function context to an instance of a new function
MyAwesomeFunction myAwesomeFunction= MyAwesomeFunction();
myAweSomeFunction.execute(functionContext);
This worked for a time but complexity started rising and more problems
came up.
So in short I wanted to throw out the blanket question of best
practices on using (onRegion/onPool/onServer), calling other functions
from within functions, what type of functions should be used on what
type of regions, and general design patterns when executing functions.
Thanks!
*Matthew Ross | Data Engineer | Pivotal*
*625 Avenue of the Americas NY, NY 10011*
*516-941-7535 <516-941-7535> | [email protected] <[email protected]> *
