Return-Path: X-Original-To: apmail-hadoop-hdfs-user-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-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 A24AAF79C for ; Sun, 31 Mar 2013 18:28:09 +0000 (UTC) Received: (qmail 11507 invoked by uid 500); 31 Mar 2013 18:28:05 -0000 Delivered-To: apmail-hadoop-hdfs-user-archive@hadoop.apache.org Received: (qmail 11130 invoked by uid 500); 31 Mar 2013 18:28:04 -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 11122 invoked by uid 99); 31 Mar 2013 18:28:04 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 31 Mar 2013 18:28:04 +0000 X-ASF-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of john.lilley@redpoint.net designates 206.225.164.219 as permitted sender) Received: from [206.225.164.219] (HELO hub021-nj-4.exch021.serverdata.net) (206.225.164.219) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 31 Mar 2013 18:27:58 +0000 Received: from MBX021-E3-NJ-2.exch021.domain.local ([10.240.4.78]) by HUB021-NJ-4.exch021.domain.local ([10.240.4.39]) with mapi id 14.02.0318.001; Sun, 31 Mar 2013 11:27:37 -0700 From: John Lilley To: "user@hadoop.apache.org" Subject: RE: Is FileSystem thread-safe? Thread-Topic: Is FileSystem thread-safe? Thread-Index: Ac4t69s0n0Xr8kvHQaCMGEqnIxCRDwAbJCIAAAcGzsA= Date: Sun, 31 Mar 2013 18:27:37 +0000 Message-ID: <869970D71E26D7498BDAC4E1CA92226B552A71D9@MBX021-E3-NJ-2.exch021.domain.local> References: <869970D71E26D7498BDAC4E1CA92226B552A6EC0@MBX021-E3-NJ-2.exch021.domain.local> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [206.168.224.109] Content-Type: multipart/alternative; boundary="_000_869970D71E26D7498BDAC4E1CA92226B552A71D9MBX021E3NJ2exch_" MIME-Version: 1.0 X-Virus-Checked: Checked by ClamAV on apache.org --_000_869970D71E26D7498BDAC4E1CA92226B552A71D9MBX021E3NJ2exch_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable From: Ted Yu [mailto:yuzhihong@gmail.com] Subject: Re: Is FileSystem thread-safe? >>FileSystem is an abstract class, what concrete class are you using (Distr= ibutedFileSystem, etc) ? Good point. I am calling FileSystem.get(URI uri, Configuration conf) with = an URI like "hdfs://server:port/..." on a remote server, so I assume it is = creating a DistributedFileSystem. However I am not finding any documentati= on discussing its thread-safety (or lack thereof), perhaps you can point me= to it? Thanks, john --_000_869970D71E26D7498BDAC4E1CA92226B552A71D9MBX021E3NJ2exch_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

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

>>FileSystem is an abst= ract class, what concrete class are you using (DistributedFileSystem, etc) = ?

Good point.  I am calling FileSyst= em.get(URI uri, Configuration conf) with an URI like “hdfs://server:p= ort/…” on a remote server, so I assume it is creating a DistributedFileSystem.&nb= sp; However I am not finding any documentation discussing its thread-safety= (or lack thereof), perhaps you can point me to it?

Thanks, john

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