From user-return-51305-apmail-hbase-user-archive=hbase.apache.org@hbase.apache.org Fri May 6 01:55:17 2016 Return-Path: X-Original-To: apmail-hbase-user-archive@www.apache.org Delivered-To: apmail-hbase-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 4F2FF19E35 for ; Fri, 6 May 2016 01:55:17 +0000 (UTC) Received: (qmail 34488 invoked by uid 500); 6 May 2016 01:55:15 -0000 Delivered-To: apmail-hbase-user-archive@hbase.apache.org Received: (qmail 34417 invoked by uid 500); 6 May 2016 01:55:15 -0000 Mailing-List: contact user-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hbase.apache.org Delivered-To: mailing list user@hbase.apache.org Received: (qmail 34403 invoked by uid 99); 6 May 2016 01:55:15 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd2-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 06 May 2016 01:55:15 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd2-us-west.apache.org (ASF Mail Server at spamd2-us-west.apache.org) with ESMTP id A32591A12E2 for ; Fri, 6 May 2016 01:55:14 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd2-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: 1.879 X-Spam-Level: * X-Spam-Status: No, score=1.879 tagged_above=-999 required=6.31 tests=[DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=2, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_PASS=-0.001] autolearn=disabled Authentication-Results: spamd2-us-west.apache.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mx2-lw-us.apache.org ([10.40.0.8]) by localhost (spamd2-us-west.apache.org [10.40.0.9]) (amavisd-new, port 10024) with ESMTP id jz9HZJjG9TxI for ; Fri, 6 May 2016 01:55:12 +0000 (UTC) Received: from mail-yw0-f181.google.com (mail-yw0-f181.google.com [209.85.161.181]) by mx2-lw-us.apache.org (ASF Mail Server at mx2-lw-us.apache.org) with ESMTPS id 616325F4EE for ; Fri, 6 May 2016 01:55:12 +0000 (UTC) Received: by mail-yw0-f181.google.com with SMTP id t10so176922876ywa.0 for ; Thu, 05 May 2016 18:55:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to; bh=prx3ZEZuj4GIjaa7tD+WIqsVveoRhb4pEIQBVEV1c7o=; b=0zP7c3/SY6IauvhyMQ0e0qY7nCi1n12acKTG7OuSQlEHXzFhKfvAU+QYHn8leSygSJ OGH5bzpis4Qrbx4g0bFauVAMWTtKkUWPdOm1Olu+WEWofzUgrqKt8rguP0SABlVZI12A 6jQRBEchu5qb6IdKWJPFDggugUkAiNms/9XjV9QKsQaagmcdQfhBcPu+tsBFFjWYQGZv fI5JTmlmd3DYPOVN1N1IVS+4nmsFe8tCvV8IUcgmxq2zl0JR+BA/e85WRTLMvjXhzV5E KTFxysHbYBtDKrlBtyZEKe8fOkcQ8H7Un8YS7oOaSpAelVT6Aejl3RIxOwA971S88toZ MEKQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to; bh=prx3ZEZuj4GIjaa7tD+WIqsVveoRhb4pEIQBVEV1c7o=; b=B4zW8Eor1343F/YVmSMaW57+p5xF8GLPKnMnJWuVmu84izx7nrdyazPvC4Nz4Qrb1R A0lVqkqAPGVWPvE3PvEsuOCxCjMlcWFwa81mY/XGVEG1TwPRkOXBFEYd+mK1N/7Kj+or /Xtq2QAwxJigVXScDDq+t9cIDooocG2pVPIYpOIHV7KbS+dMMR+G1+wbuPGEZYNQUDI6 1wD6rBpt0JfYRA8hg7a0kC7KM+5HGbu68Lul5GJvuhiDqSevxFtAjJwqXnbEkUL6FuV2 HOHWUnxpfcjHYqeQtlRIbmiZWOMufx0KmwUMOF/IQalfgkXqPcOcLSHyeVSkKne+Zn5R 5XvQ== X-Gm-Message-State: AOPr4FUayQjFKcsAhIdtxzebs3BI4wdFCkYPCLEbJQm3yt0Ev0yFEmGbUQpf/S5h/AFLiKVd27hzCtgKYw9D3g== MIME-Version: 1.0 X-Received: by 10.129.4.216 with SMTP id 207mr11970006ywe.184.1462499711807; Thu, 05 May 2016 18:55:11 -0700 (PDT) Received: by 10.37.37.142 with HTTP; Thu, 5 May 2016 18:55:11 -0700 (PDT) In-Reply-To: References: Date: Thu, 5 May 2016 18:55:11 -0700 Message-ID: Subject: Re: hbase doubts From: Ted Yu To: "user@hbase.apache.org" Content-Type: multipart/alternative; boundary=001a113f19d4ce7a20053222bfdb --001a113f19d4ce7a20053222bfdb Content-Type: text/plain; charset=UTF-8 For #3, we already have the following in 1.1 release: HBASE-10201 Port 'Make flush decisions per column family' to trunk On Thu, May 5, 2016 at 6:36 PM, Shushant Arora wrote: > 1.Why is it better to have single file per region than multiple files for > read performance. Why can't multile threads read multiple file and give > better performance? > > 2Does hbase regionserver has single thread for compactions and split for > all regions its holding? Why can't single thread per regions will work > better than sequential compactions/split for all regions in a regionserver. > > 3.Why hbase flush and compact all memstores of all the families of a table > at same time irrespective of their size when even one memstore reaches > threshold. > > Thanks > Shushant > --001a113f19d4ce7a20053222bfdb--