<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><BR><DIV><DIV>On Oct 3, 2007, at 23:48, Clint Webb wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; ">I personally do not see the need to use tags in any other way except to easily remove (invalidate?) keys that have a particular tag. Being able to do other things like retrieve all keys that have a tag, could be useful, but I can see it as complicating things.<SPAN class="Apple-converted-space"> </SPAN><BR></SPAN></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>It's not that it it's complicated, but it falls under the same category of listing keys that causes the server to hang while someone calls it.</DIV><BR><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; ">First point. When you say 'invalidate_tag' I assume you mean to invalidate all keys that have that tag.<BR></SPAN></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>Correct.</DIV><BR><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; ">Second point. You ask the question about refcounts on tags, I think it should, or at the very least provide a command that will tell the cache to remove all tags that are no longer referenced by a key. Refcount is probably easier, and just remove the tag when it gets to zero. Decrementing it when a key is deleted or expired. Otherwise, memory used by tags will always keep getting bigger as keys drop out due to LRU. An example, article 50 is added to the cache, and tags representing that article ID have been added to a bunch of keys. Over time, article 50 no longer has much visibility and falls out of the cache due to LRU. If no more keys are in the cache for the tag, I think the tag should go. <SPAN class="Apple-converted-space"> </SPAN><BR></SPAN></BLOCKQUOTE><DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>It really depends on how often a tag is *not* used again. If tags are generally reused, it makes things more expensive and complicated. It could also lead to a lot of memory churn unless there's a memory pool for tags as well.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>If tags are often not reused, it would be a memory leak.</DIV><BR><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; ">Third point. I am also assuming that we can assign more than one tag to a key. If I could only add one tag to a key, then that would limit its usefulness to me. I see you mention pointers (and not just pointer) so I am sure that this is correct, just clarifying.<SPAN class="Apple-converted-space"> </SPAN><BR></SPAN></BLOCKQUOTE></DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><SPAN class="Apple-tab-span" style="white-space:pre"> </SPAN>Absolutely. Each item may have zero or more tags.</DIV><BR><DIV> <SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><DIV>-- </DIV><DIV>Dustin Sallings</DIV><BR class="Apple-interchange-newline"></SPAN> </DIV><BR></BODY></HTML>