Return-Path: X-Original-To: apmail-hadoop-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-user-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 18BBEF1DC for ; Sun, 31 Mar 2013 18:52:54 +0000 (UTC) Received: (qmail 68371 invoked by uid 500); 31 Mar 2013 18:52:49 -0000 Delivered-To: apmail-hadoop-user-archive@hadoop.apache.org Received: (qmail 68062 invoked by uid 500); 31 Mar 2013 18:52:49 -0000 Mailing-List: contact user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@hadoop.apache.org Delivered-To: mailing list user@hadoop.apache.org Received: (qmail 68054 invoked by uid 99); 31 Mar 2013 18:52:49 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 31 Mar 2013 18:52:49 +0000 X-ASF-Spam-Status: No, hits=1.5 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of yuzhihong@gmail.com designates 209.85.215.54 as permitted sender) Received: from [209.85.215.54] (HELO mail-la0-f54.google.com) (209.85.215.54) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 31 Mar 2013 18:52:43 +0000 Received: by mail-la0-f54.google.com with SMTP id gw10so1641013lab.13 for ; Sun, 31 Mar 2013 11:52:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:content-type; bh=uhxX1LIcccGAGiyXZKipsSGLF3mEBpj1HpONVxw2I4w=; b=SN4SsdfrIj0IkNU0ooqgsw9Kr7aW2UjuX14FnOxNZIkw+/sjDIwPP1Dmw82u72Wjyb tTRDcGVqPgnL1bocg9HtBHxSLEZzLGi4pNLDZztMxjABs4CejWt3dRAj3Eb8FqxAE1/t QbaJErON/qNMGN5Sjt3kBIOsb1Nc1NnIgZFJ5VvuASY/0DW8NwAjop0SLBNiOtMFvUoy 6pv35M0k+1zApN8ovRLvug5T4h8jzcWa/2zob1dB70WQCGLJpErKnL3cz6obJPKsKzkO cML93wtNkjH6Bqu8vaB4m1SsbZ4Hhicc/dZDRgTzKkF3QB1/cuNkmIeSq+SEJXaYAdXh ZnCQ== MIME-Version: 1.0 X-Received: by 10.152.133.130 with SMTP id pc2mr4346027lab.51.1364755942886; Sun, 31 Mar 2013 11:52:22 -0700 (PDT) Received: by 10.112.84.133 with HTTP; Sun, 31 Mar 2013 11:52:22 -0700 (PDT) In-Reply-To: <869970D71E26D7498BDAC4E1CA92226B552A71D9@MBX021-E3-NJ-2.exch021.domain.local> References: <869970D71E26D7498BDAC4E1CA92226B552A6EC0@MBX021-E3-NJ-2.exch021.domain.local> <869970D71E26D7498BDAC4E1CA92226B552A71D9@MBX021-E3-NJ-2.exch021.domain.local> Date: Sun, 31 Mar 2013 11:52:22 -0700 Message-ID: Subject: Re: Is FileSystem thread-safe? From: Ted Yu To: "common-user@hadoop.apache.org" Content-Type: multipart/alternative; boundary=f46d042dfc872e50be04d93d0157 X-Virus-Checked: Checked by ClamAV on apache.org --f46d042dfc872e50be04d93d0157 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable If you look at DistributedFileSystem source code, you would see that it calls the DFSClient field member for most of the actions. Requests to Namenode are then made through ClientProtocol. An hdfs committer would be able to give you affirmative answer. On Sun, Mar 31, 2013 at 11:27 AM, John Lilley wro= te: > *From:* Ted Yu [mailto:yuzhihong@gmail.com] > *Subject:* Re: Is FileSystem thread-safe?**** > > >>FileSystem is an abstract class, what concrete class are you using > (DistributedFileSystem, etc) ? **** > > Good point. I am calling FileSystem.get(URI uri, Configuration conf) wit= h > an URI like =93hdfs://server:port/=85=94 on a remote server, so I assume = it is > creating a DistributedFileSystem. However I am not finding any > documentation discussing its thread-safety (or lack thereof), perhaps you > can point me to it?**** > > Thanks, john**** > --f46d042dfc872e50be04d93d0157 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable
If you look at DistributedFileSystem source code, you woul= d see that it calls the DFSClient field member for most of the actions.Requests to Namenode are then made through ClientProtocol.

An hdfs committer would be able to give you affirmative answer.<= /div>


On Sun, Mar 31, 2013 at 11:27 AM, John Lilley <john.lilley@redp= oint.net> wrote:

From: Ted Yu [= mailto:yuzhihong@g= mail.com]
Subject: Re: Is FileSystem thread-safe?

>>FileSys= tem is an abstract class, what concrete class are you using (DistributedFil= eSystem, etc) ?

Good point.=A0 I am= calling FileSystem.get(URI uri, Configuration conf) with an URI like =93hd= fs://server:port/=85=94 on a remote server, so I assume it is creating a DistributedFileSystem.=A0= However I am not finding any documentation discussing its thread-safety (o= r lack thereof), perhaps you can point me to it?

Thanks, john


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