<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On 21 Nov 2011, at 09:34, Galder Zamarreņo wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><br>On Nov 17, 2011, at 4:39 PM, Slorg1 wrote:<br><br><blockquote type="cite">Hi all,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">See comment below,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On Thu, Nov 17, 2011 at 10:20, Galder Zamarreņo <<a href="mailto:galder@redhat.com">galder@redhat.com</a>> wrote:<br></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">On Nov 17, 2011, at 2:54 PM, Manik Surtani wrote:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">On 17 Nov 2011, at 09:30, Galder Zamarreņo wrote:<br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Hi,<br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Forcing caches to be either transactional or non transactional caches causes some issues with operations such as putForExternalRead with default configuration options.<br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">Assuming we have a transactional cache, if autoCommit is on (default), putForExternalRead will:<br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">1. Suspend the ongoing transaction<br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">2. Will create a brand new transaction due to implicit transaction creation logic in auto commit.<br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">This is not good.<br></blockquote></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><blockquote type="cite">What's not good about this? 1 is by design and is correct behaviour. 2 should not affect anything, since the new tx is completed at the end of the PFER invocation.<br></blockquote></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">2 does not affect anything but seems wasteful to me. Why start a transaction when I don't need one?<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">I do not understand the need for #1 to happen given that a running<br></blockquote><blockquote type="cite">transaction already exist. In the case of a replicated cache, that<br></blockquote><blockquote type="cite">transaction exists remotely on all other nodes.<br></blockquote><blockquote type="cite">Thus why not apply the put under the same scope ?<br></blockquote><br>It's an optimisation since we're reading from the external source of data. This optimisation avoids locking issues as a result of trying to read the same piece of data into the cache when executed concurrently in different nodes.<br><br>Read the putForExternal read javadoc to find out more.<br></span></blockquote><br></div><div>It's not so much locking issues as it is that the pFER operation cannot and will not cause the database operation to fail/rollback. And this is important. Since in this use case, Infinispan is used as a throwaway cache. If we can't cache a DB read for some reason, we shouldn't fail the whole transaction. And hence the suspending/starting a new transaction for the pFER operation.</div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><div>--</div><div>Manik Surtani</div><div><a href="mailto:manik@jboss.org">manik@jboss.org</a></div><div><a href="http://twitter.com/maniksurtani">twitter.com/maniksurtani</a></div><div><br></div><div>Lead, Infinispan</div><div><a href="http://www.infinispan.org">http://www.infinispan.org</a></div><div><br></div></div></span><br class="Apple-interchange-newline">
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