Return-Path: X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by cust-asf2.ponee.io (Postfix) with ESMTP id A62BC200BAF for ; Mon, 31 Oct 2016 15:36:19 +0100 (CET) Received: by cust-asf.ponee.io (Postfix) id A4931160B05; Mon, 31 Oct 2016 14:36:19 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id 1FF80160AF0 for ; Mon, 31 Oct 2016 15:36:18 +0100 (CET) Received: (qmail 29906 invoked by uid 500); 31 Oct 2016 14:36:18 -0000 Mailing-List: contact dev-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@accumulo.apache.org Delivered-To: mailing list dev@accumulo.apache.org Received: (qmail 29881 invoked by uid 99); 31 Oct 2016 14:36:18 -0000 Received: from git1-us-west.apache.org (HELO git1-us-west.apache.org) (140.211.11.23) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 31 Oct 2016 14:36:18 +0000 Received: by git1-us-west.apache.org (ASF Mail Server at git1-us-west.apache.org, from userid 33) id EFFBEE1075; Mon, 31 Oct 2016 14:36:17 +0000 (UTC) From: joshelser To: dev@accumulo.apache.org Reply-To: dev@accumulo.apache.org References: In-Reply-To: Subject: [GitHub] accumulo pull request #176: Wrote blog post about durability and performance Content-Type: text/plain Message-Id: <20161031143617.EFFBEE1075@git1-us-west.apache.org> Date: Mon, 31 Oct 2016 14:36:17 +0000 (UTC) archived-at: Mon, 31 Oct 2016 14:36:19 -0000 Github user joshelser commented on a diff in the pull request: https://github.com/apache/accumulo/pull/176#discussion_r85750520 --- Diff: _posts/blog/2016-10-28-durability-performance.md --- @@ -0,0 +1,136 @@ +--- +title: "Durability Performance Implications" +date: 2016-10-28 17:00:00 +0000 +author: Keith Turner +--- + +## Overview + +Accumulo stores recently written data in a sorted in memory map. Before data is +added to this map, it's written to an unsorted WAL (write ahead log). In the +case when a Tablet Server dies, the recently written data is recovered from the +WAL. + +When data is written to Accumulo the following happens : + + * Client sends a batch of mutations to a tablet server + * Tablet server does the following : + * Writes mutation to Tablet Servers WAL + * Sync or flush WAL + * Adds mutations to sorted in memory maps --- End diff -- My apologies! Ignore this one then. --- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. If your project does not have this feature enabled and wishes so, or if the feature is enabled but not working, please contact infrastructure at infrastructure@apache.org or file a JIRA ticket with INFRA. ---