" potential 5% performance win when you've corrupted all their data." This is somewhat of my point. Why do assertions that sometimes are trapped "protect my data" better then a checked exception?
On Wed, Sep 21, 2016 at 1:24 PM, Michael Kjellman < mkjell...@internalcircle.com> wrote: > I hate that comment with a passion. Please please please please do > yourself a favor and *always* run with asserts on. `-ea` for life. In > practice I'd be surprised if you actually got a reliable 5% performance win > and I doubt your customers will care about a potential 5% performance win > when you've corrupted all their data. > > best, > kjellman > > > On Sep 21, 2016, at 10:21 AM, Edward Capriolo <edlinuxg...@gmail.com> > wrote: > > > > There are a variety of assert usages in the Cassandra. You can find > several > > tickets like mine. > > > > https://issues.apache.org/jira/browse/CASSANDRA-12643 > > > > https://issues.apache.org/jira/browse/CASSANDRA-11537 > > > > Just to prove that I am not the only one who runs into these: > > > > https://issues.apache.org/jira/browse/CASSANDRA-12484 > > > > To paraphrase another ticket that I read today and can not find, > > "The problem is X throws Assertion which is not caught by the Exception > > handler and it bubbles over and creates a thread death." > > > > The jvm.properties file claims this: > > > > # enable assertions. disabling this in production will give a modest > > # performance benefit (around 5%). > > -ea > > > > If assertions incur a "5% penalty" but are not always trapped what value > do > > they add? > > > > These are common sentiments about how assert should be used: (not trying > to > > make this a this is what the internet says type debate) > > > > http://stackoverflow.com/questions/2758224/what-does- > the-java-assert-keyword-do-and-when-should-it-be-used > > > > "Assertions > > <http://docs.oracle.com/javase/specs/jls/se8/html/jls-14.html#jls-14.10> > (by > > way of the *assert* keyword) were added in Java 1.4. They are used to > > verify the correctness of an invariant in the code. They should never be > > triggered in production code, and are indicative of a bug or misuse of a > > code path. They can be activated at run-time by way of the -eaoption on > the > > java command, but are not turned on by default." > > > > http://stackoverflow.com/questions/1957645/when-to-use- > an-assertion-and-when-to-use-an-exception > > > > "An assertion would stop the program from running, but an exception would > > let the program continue running." > > > > I look at how Cassandra uses assert and how it manifests in how the code > > operates in production. Assert is something like semi-unchecked > exception. > > All types of internal Util classes might throw it, downstream code is > > essentially unaware and rarely specifically handles it. They do not > always > > result in the hard death one would expect from an assert. > > > > I know this is a ballpark type figure, but would "5% performance penalty" > > be in the ballpark of a checked exception? Being that they tend to bubble > > through things uncaught do they do more danger than good? > >
