Re: Failed transactions

Thanks very much for the clarifications, and the code.


R


On Aug 1, 2009, at 8:54 PM, Klaus Wuestefeld wrote:

>> The other types, "deterministic" are like when a parameter that must
>> be validated at transaction time fails.  Existence of a dependent
>> object for example.  I have to test within the execution of
>> transaction to guarantee state.   When that fails, I wonder what the
>> expected state of the journal is.
>
> The transaction is written to the journal before being applied to the
> system (to ensure durability of reads) and never removed.
>
> The food taster turned on (Justin please confirm) will prevent such
> faulty transactions from being written to the log.
>
> The food taster is rebuilt in RAM as a copy of the actual system.
> Piped serialization in RAM is used to make the copy. All transactions
> are blocked while that happens.
>
> This is how I measure used RAM:
>
> 	static private final Runtime RUNTIME = Runtime.getRuntime();
>
> 	private int measureUsedMemory() {
> 		long total, total2, free;
> 		do {
> 			total = RUNTIME.totalMemory();
> 			free = RUNTIME.freeMemory();
> 			total2 = RUNTIME.totalMemory();
> 		} while (total != total2);
> 			
> 		return total - free;
> 	}
>
> And calling RUNTIME.maxMemory() you get the max given to the VM. I
> wouldn't resort to JMX unless I wanted to monitor remotely, and maybe
> not even then.
>
> See you, Klaus.
>
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