replication

问题 I am trying to run pt-table-sync to re-synchronise a MYSQL Master-Slave replication. I have two VPS Systems which are running Debian 5, and the replication is running without any issues. The problem I have is that when I run pt-table-sync on the MASTER server, it keeps failing to connect to the SLAVE server. I am running the following command: pt-table-sync --dry-run --sync-to-master h='ip of slave server',u='user',p='password' Which returns: Host 'my website address' is not allowed to

问题 Suppose I have 15 blocks of data and two clusters. The first cluster has 5 nodes and a replication factor is 1, while the second one has a replication factor is 3. If I run my map job, should I expect any change in the performance or the execution time of the map job? In other words, how does replication affect the performance of the mapper on a cluster? 回答1: When the JobTracker assigns a job to a TaskTracker on HDFS, a job is assigned to a particular node based upon locality of data

问题 Most guidelines recommend to use mongodump/mongorestore, but for large product databases downtime can be very long 回答1: You can use replication and an additional server for this or the same server if the load allows. You need 3 running MongoDB instance: Your server you want to update (remind that WiredTiger support since 3.0). Second instance of MongoDB which can be run on an additional server. Database will be temporarily copied to it by the replication. And the third instance of MongoDB is

问题 The question is rather simple, but I can't find any documentation on it: How can I mirror specific tables from a database to another? The basic idea is having twin databases that share only specific tables between them Any advice will be appreciated! If PostgreSQL can't do it, is there another RDBMS that can? Thanks in advance! EDIT : The reason I want to do this is to share "arbitrary" info across two databases using django, without losing proper referential integrity. For example: Let's say

问题 i have successfully installed ubuntu 12.04 and hadoop 2.3.0. after entering the jps command i find the output as below 4135 jps 2582 SeconadaryNameNode 3143 NodeManager 2394 Namenode 2391 Datanode 3021 ResourceManager why it is not showing the jobtracker and tasktracker. i tried start-mapred.sh but it shows command not found.(i searched the hadoop directory no such file found so i think the newer version i.e 2.0.3 has deprecated it and must be having some other way of starting jobtracker and

问题 My company currently has a transactional db running on Sql Server 2005. We are going to add a MySql (running on linux) reporting db. We'll need to get replication running from the MS-Sql db to the MySql db. It doesn't have to be real time but should be within a few minutes. I've got pretty good MSSql Dev skills and so-so dba skills but no MySql background. The MySql guy on our team has no MSSql experience. I was wondering if anybody has setup anything similar and might have some suggestions.

问题 Lets say we have 3 servers on a local area network: APP - php app server MASTER - master Mysql db server SLAVE - slave Mysql db server (replicating MASTER) In the one code block (php) APP inserts into MASTER , retrieving the last_insert_id which it then uses to select the data it just inserted from SLAVE . So the question is, will the replication have happened in time for SLAVE to have the data from MASTER ? Is this influenced by load put on either MASTER or SLAVE ? And lastly, if there is a

问题 We are currently evaluating failover support in different databases. We were earlier using HSQLDB but it seems that it does not have clustering/replication support. Our requirement is simply to have two database servers, one being only for synchronous backup but if the primary server is down, then the secondary should automatically start acting as the primary server. Has anyone evaluated MySQL, PostgreSQL or any other DB server for such a use case? Edit: We had thought of using MySQL cluster

问题 I have configured the replication with following configurations $cat /var/gerrit/review_site/etc/replication.config [gerrit] autoReload=true [remote "bt-git"] projects = ^vt-(.*)$ push = refs/heads/*:refs/heads/* url = git@git.something.com:/${name}.git My ssh config file looks like this one, Host git HostName git.something.com User git IdentityFile /var/gerrit/.ssh/id_rsa StrictHostKeyChecking no UserKnownHostsFile /dev/null Although I have already added the right set of hostkeys in my ~/

问题 I'm building a system where multiple users need to create, view and modify a set of objects concurrently. The system is planned to run on a Java server and modern browser clients (I get to pick which ones). It needs to be robust in face of network and server outages, the user interface must not block for modifications, modifications need to be stored locally and published when connectivity returns. Under normal operation changes should replicate with sub-second latency. Network latency and