From oak-issues-return-42896-apmail-jackrabbit-oak-issues-archive=jackrabbit.apache.org@jackrabbit.apache.org Thu Dec 22 14:37:59 2016 Return-Path: X-Original-To: apmail-jackrabbit-oak-issues-archive@minotaur.apache.org Delivered-To: apmail-jackrabbit-oak-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id DAF4919BC0 for ; Thu, 22 Dec 2016 14:37:58 +0000 (UTC) Received: (qmail 63523 invoked by uid 500); 22 Dec 2016 14:37:58 -0000 Delivered-To: apmail-jackrabbit-oak-issues-archive@jackrabbit.apache.org Received: (qmail 63469 invoked by uid 500); 22 Dec 2016 14:37:58 -0000 Mailing-List: contact oak-issues-help@jackrabbit.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: oak-dev@jackrabbit.apache.org Delivered-To: mailing list oak-issues@jackrabbit.apache.org Received: (qmail 63288 invoked by uid 99); 22 Dec 2016 14:37:58 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 22 Dec 2016 14:37:58 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id 7BF452C2A66 for ; Thu, 22 Dec 2016 14:37:58 +0000 (UTC) Date: Thu, 22 Dec 2016 14:37:58 +0000 (UTC) From: =?utf-8?Q?Michael_D=C3=BCrig_=28JIRA=29?= To: oak-issues@jackrabbit.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (OAK-5042) Improve caching of segments MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/OAK-5042?page=3Dcom.atlassian.= jira.plugin.system.issuetabpanels:all-tabpanel ] Michael D=C3=BCrig updated OAK-5042: ------------------------------- Labels: performance scalability (was: performance) > Improve caching of segments > --------------------------- > > Key: OAK-5042 > URL: https://issues.apache.org/jira/browse/OAK-5042 > Project: Jackrabbit Oak > Issue Type: Improvement > Components: segment-tar > Reporter: Michael D=C3=BCrig > Assignee: Michael D=C3=BCrig > Labels: performance, scalability > Fix For: 1.8 > > Attachments: OAK-5042.png > > > Various aspects of how Segment Tar caches segments could possibly improve= d. The current cache is a result of replacing the former ad-hoc cache with = a proper one in OAK-3055. While the former was prone to contention under co= ncurrent load the current cache is too oblivious about reads: read accesses= are always served through {{SegmentId.segment}} and never actually hit the= cache. This results in frequently accessed segments not to be seen as such= by the cache and potentially being prematurely evicted.=20 > Possibly approaches to address this problem include:=20 > * Reinstantiating the cache we had pre OAK-3055 but making in fully concu= rrent.=20 > * Convey the information about read accesses to the current cache.=20 > * In either of the above cases avoid bulk segments from being placed into= the cache.=20 -- This message was sent by Atlassian JIRA (v6.3.4#6332)