Return-Path: X-Original-To: apmail-accumulo-notifications-archive@minotaur.apache.org Delivered-To: apmail-accumulo-notifications-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 9514D100D7 for ; Thu, 22 Jan 2015 18:15:34 +0000 (UTC) Received: (qmail 82062 invoked by uid 500); 22 Jan 2015 18:15:34 -0000 Delivered-To: apmail-accumulo-notifications-archive@accumulo.apache.org Received: (qmail 82023 invoked by uid 500); 22 Jan 2015 18:15:34 -0000 Mailing-List: contact notifications-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: jira@apache.org Delivered-To: mailing list notifications@accumulo.apache.org Received: (qmail 82008 invoked by uid 99); 22 Jan 2015 18:15:34 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 22 Jan 2015 18:15:34 +0000 Date: Thu, 22 Jan 2015 18:15:34 +0000 (UTC) From: "marco polo (JIRA)" To: notifications@accumulo.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Created] (ACCUMULO-3510) Create mechanism to support priority based scheduling of read ahead tasks. MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 marco polo created ACCUMULO-3510: ------------------------------------ Summary: Create mechanism to support priority based scheduling of read ahead tasks. Key: ACCUMULO-3510 URL: https://issues.apache.org/jira/browse/ACCUMULO-3510 Project: Accumulo Issue Type: Improvement Components: tserver Affects Versions: 1.6.0 Reporter: marco polo Priority: Minor Fix For: 1.6.3 I have many cases where ScanSessions will consume resources that I otherwise want shorter running scans to utilize. In some cases, a scan may continue for hours, while a short running scan may come in and execute quickly. As a result, I want to be able to adjust the priority of these scan sessions. I have a patch which is forthcoming, that breaks Session out of TabletServer and replaces the queue in the readAheadThreadPool with a priority pool. The comparator I have created as a proof of concept, which can be adjustable, reduces the priority of the oldest scan. Using an aging technique, we guarantee execute of these older running scans based upon the previous run time. As a result, we give preference to newer scans. If they execute quickly, older scans will have an inherent rise in priority. If they also take a while, their priority will be reduced and incoming scans will yet again be given a greater priority with the intent (and/or hope ) their execution will be faster. Priority should be configurable based on the desired Session Comparator. -- This message was sent by Atlassian JIRA (v6.3.4#6332)