Changes between Initial Version and Version 1 of AnugaCheckpoints

Timestamp:

Jun 15, 2010, 9:38:32 AM (15 years ago)

Author:

James Hudson

Comment:

--

AnugaCheckpoints

@@ +1 @@
+= ANUGA Checkpoints =
+
+Since ANUGA may take a long time to run a simulation, it can be prudent to save off the partial results at different stages of execution in case of hardware failure or power loss.
+
+== cPickle Method ==
+
+Many people have requested restore point functionality in ANUGA to deal with interruptions to a running script. Python already has the ability to save state to a file using the cPickle module.
+
+You can use code like this in your application to implement restore points:
+
+{{{
+import cPickle
+
+start_time = 0.0
+if use_restore_point is True:
+    print 'resuming from restore point...'
+    domain = cPickle.load(open('domain_pickle.txt'))
+    start_time = domain.time
+else:
+    # do your normal domain initialisation here
+
+
+for restorepoint in range(start_time, 10):
+    # evolve domain in small chunks, regularly pickling a restore point
+    for t in domain.evolve(yieldstep=0.1, finaltime=restorepoint):
+        pass
+    print 'saving restore point...'
+    cPickle.dump(domain, open('domain_pickle.txt', 'w'))
+}}}
+
+== use_cache Method ==
+ANUGA also has inbuilt caching functionality. You can set the use_cache = True parameter on many functions, and the results of the operation will be stored on disk for the next time the same operation is executed.