From user-return-12269-archive-asf-public=cust-asf.ponee.io@zookeeper.apache.org Tue Oct 29 05:59:31 2019 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [207.244.88.153]) by mx-eu-01.ponee.io (Postfix) with SMTP id 13BE21804BB for ; Tue, 29 Oct 2019 06:59:30 +0100 (CET) Received: (qmail 1210 invoked by uid 500); 29 Oct 2019 05:59:29 -0000 Mailing-List: contact user-help@zookeeper.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@zookeeper.apache.org Delivered-To: mailing list user@zookeeper.apache.org Received: (qmail 1196 invoked by uid 99); 29 Oct 2019 05:59:28 -0000 Received: from Unknown (HELO mailrelay1-lw-us.apache.org) (10.10.3.42) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 29 Oct 2019 05:59:28 +0000 Received: from [192.168.1.28] (5402D637.dsl.pool.telekom.hu [84.2.214.55]) by mailrelay1-lw-us.apache.org (ASF Mail Server at mailrelay1-lw-us.apache.org) with ESMTPSA id 7CAA959FA for ; Tue, 29 Oct 2019 05:59:28 +0000 (UTC) From: Andor Molnar Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Subject: Re: Why are errors stored in the transaction logs? Date: Tue, 29 Oct 2019 06:59:26 +0100 References: <5c03507e-8b10-c6f2-c41b-d4a7475ecab1@apache.org> To: user@zookeeper.apache.org In-Reply-To: <5c03507e-8b10-c6f2-c41b-d4a7475ecab1@apache.org> Message-Id: <3426043F-FB61-45B9-AE44-1B8372F0BA97@apache.org> X-Mailer: Apple Mail (2.3445.104.11) Hi Sylvain, That should not be the case. Txns are not going to be created from read = requests and not hit SyncRequestProcessor which is responsible for = maintaining txn and snap logs. The error handling you see in processTxn() is for ignoring failures = during log replaying inside processTxn() method (in the catch branch). = Introduced in ZOOKEEPER-1269 and it=E2=80=99s related to multis afaics. Andor > On 2019. Oct 15., at 16:33, Sylvain Wallez wrote: >=20 > Hi ZooKeepers, >=20 > We had an issue recently with a service hammering ZK to read a path = that doesn't exist. As a result the transaction logs grew quickly = because errors are stored there. >=20 > Looking at DataTree.processTxn() which is called from = FileTxnSnapLog.restore() it seems that errors read in the transaction = log are essentially ignored. >=20 > So what is storing errors in the txnlog useful for? Would it make = sense to have a configuration flag to not store them? >=20 > Thanks, > Sylvain >=20