Hi,
When you start the compute task then it (and code from there) will be
executed on every server (that were chosen) consistently in the single
thread.
But if you will try to broadcast the same task on several servers then
race between different tasks on different servers is possible in this
case. To avoid it you can try to use the transactions API (to provide
atomicity of get-update-put operation) or distributed locks for updated
keys:
https://apacheignite.readme.io/docs/transactions
https://apacheignite.readme.io/docs/distributed-locks
<https://apacheignite.readme.io/docs/distributed-locks>
BR,
Andrei
9/5/2019 5:41 PM, Ari Erev пишет:
Hello,
This question is related to the question by “humenius”, with subject:
“Race condition and conflicts during cache modifications?” – but I
believe it is a simpler case…
When code is run on an Ignite server node (such as from a distributed
compute, or service) – is all access to a specific object (object
with a specific key) – done from one (the same) specific thread?
The reason I am asking is this:
Some examples of Ignite code on GitHub and the ones that are embedded
in White Paper articles from GridGain contain the following conceptual
code (incrementing a value in the cache).
My_Object obj = cache.get(key);
obj.increment_value();
cache.put(key, obj);
If this code is executed concurrently from more than one thread, there
is a risk for inconsistency, as the new/incremented value may
overwrite a cached value which is already different than it was at the
time of the cache.get().
If so, should such code be synchronized (use some sort of lock)?
Thanks,
Ari
Confidentiality: This communication and any attachments are intended
for the above-named persons only and may be confidential and/or
legally privileged. Any opinions expressed in this communication are
not necessarily those of NICE Actimize. If this communication has come
to you in error you must take no action based on it, nor must you copy
or show it to anyone; please delete/destroy and inform the sender by
e-mail immediately.
Monitoring: NICE Actimize may monitor incoming and outgoing e-mails.
Viruses: Although we have taken steps toward ensuring that this e-mail
and attachments are free from any virus, we advise that in keeping
with good computing practice the recipient should ensure they are
actually virus free.
