Not sure if there's a "built-in" approach in Storm for doint that. After
make sure there isn't, I'd do the following
* I'd start such long task asynchronously in the prepare method and
I'd register a callback
* if the execute method logic depends on the completion of such task,
I'd use a basic state pattern with two states ON/OFF (where the off
state is basically a NullObject). The callback would be responsible
to switch the bolt state from OFF (initial state) to ON (working state)
Best,
Andrea
On 23/08/16 09:12, Xiang Wang wrote:
Hi All,
I am trying to do some long-time initialisation task in bolt prepare()
method in local mode.
I always got error like this:
*WARN o.a.s.s.o.a.z.s.p.FileTxnLog - fsync-ing the write ahead log in
SyncThread:0 took 1197ms which will adversely effect operation
latency. See the ZooKeeper troubleshooting guide*
And then the task fails.
Could anyone tell me how to fix this problem? Or is it a good practice
to run long-time task in prepare() method? If not, what is supposed to
be the correct way to do it?
Many thanks for your kind help.
Best,
Xiang
-------------------------------
Xiang Wang, PhD Candidate
Database Research Group
School of Computer Science and Engineering
The University of New South Wales
SYDNEY, AUSTRALIA
