Hi there- As a reminder about running without an NTP server, the config section of the book strongly cautions against this:
http://hbase.apache.org/book.html#ntp On 10/25/11 10:36 PM, "Gaojinchao" <[email protected]> wrote: >Thanks for your reply. >Our application scenario, The equipment and network is not our, Operators >may do some of the equipment and network adjustment. >In this case, These are some of the uncertainties. >So we hope to add a choice about metadata is not time-dependent. Just >like use data can use a number as a timestamp . >If we can do this, the effect for time will be smaller. We don't use the >ntp server, the cluster also can work normal ? >Can I open a file? I will try to make a patch and share my mind. > >-----邮件原件----- >发件人: Michel Segel [mailto:[email protected]] >发送时间: 2011年10月26日 3:55 >收件人: [email protected] >抄送: [email protected] >主题: Re: A requirement to change time of the Hbase cluster. > >Maybe I'm missing something... > >The purpose of using an ntp server is that your machines all have the >same time. Also you would sync your ntp server clock to one of the global >ntp servers so that you have an accurate clock for your network... > >You shouldn't have to restart your cluster unless your clocks are all way >off... > >Sent from a remote device. Please excuse any typos... > >Mike Segel > >On Oct 25, 2011, at 5:14 AM, Gaojinchao <[email protected]> wrote: > >> Perhaps we should. add a choice of supporting incremental meta-data. >>All the timestamp is incremental, These data do not rely on the system >>time. >> >> -----邮件原件----- >> 发件人: Gaojinchao [mailto:[email protected]] >> 发送时间: 2011年10月25日 12:33 >> 收件人: [email protected] >> 主题: A requirement to change time of the Hbase cluster. >> >> Hi all, >> We have a requirement to change time of the Hbase cluster. >> The scene is the cluster changes the ntp server(my customer may do >>this), >> We are ready to do this: >> 1. stop the cluster >> 2. change the ntp server >> 3. start the cluster. >> But the cluster may move to one ntp server which system is slower. >> we find the meta data can't update becuase newly added record is >>covered by old record and the cluster don't run normal. >> I have a way to deal with this situation. before we update the meta >>data ,we can get it firstly and then compare the timestamp with the >>system time. >> if system time is lower than timestamp, updating metadata can use as >>timestamp +1.
