mongodb replication

十字螺丝钉

<DIV>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">mongodb<FONT face=宋体>一个主库可以带一个或者多个（对于从库的数量没有明确的限制）从库，每一个从库都要知道主库的地址。</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">-----</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">实验步骤</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">start&nbsp;master</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">[root@biee&nbsp;bin]#&nbsp;./mongod&nbsp;--port&nbsp;10000&nbsp;--master</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">start&nbsp;slave</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">[root@standby&nbsp;bin]#&nbsp;./mongod&nbsp;--port&nbsp;10001&nbsp;--slave&nbsp;--source&nbsp;172.16.0.67:10000</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN>&nbsp;</P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">进入到<FONT face="Times New Roman">mongo</FONT><FONT face=宋体>中，打</FONT><FONT face="Times New Roman">./mongo</FONT><FONT face=宋体>会出错，正确格式如下</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">进入到<FONT face="Times New Roman">master</FONT><FONT face=宋体>的</FONT><FONT face="Times New Roman">shell</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">./mongo&nbsp;172.16.0.67:10000</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">进入到<FONT face="Times New Roman">slave</FONT><FONT face=宋体>的</FONT><FONT face="Times New Roman">shell</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">./mongo&nbsp;172.16.0.68:10001</SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN>&nbsp;</P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">mongodb replication同步数据</SPAN></P><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">**********</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">Syncing**<FONT face=宋体>同步</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">**********</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">当一个从库启动时，它将和主库做一个完全同步。从库复制主库的每一个<FONT face="Times New Roman">document</FONT><FONT face=宋体>，不过这个操作代价很高。初始化同步操作完成后，从库查询主库的</FONT><FONT face="Times New Roman">oplog</FONT><FONT face=宋体>并应用，为以后同步数据做好准备。</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P>
<P class=p0 style="MARGIN-TOP: 0pt; MARGIN-BOTTOM: 0pt"><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'">如果从库远远落后主库，从库会同步失败<FONT face="Times New Roman">(fall&nbsp;out&nbsp;of&nbsp;sync)</FONT><FONT face=宋体>。同步失败的从库不能够通过应用日志来赶上主库，因为主库</FONT><FONT face="Times New Roman">oplog</FONT><FONT face=宋体>记录的操作太新了</FONT><FONT face="Times New Roman">(</FONT><FONT face=宋体>由于</FONT><FONT face="Times New Roman">capped</FONT><FONT face=宋体>引起，</FONT><FONT face="Times New Roman">capped</FONT><FONT face=宋体>是个循环写，当</FONT><FONT face="Times New Roman">oplog</FONT><FONT face=宋体>满之后，新数据会将老数据覆盖）。</FONT></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></P></SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Times New Roman'; mso-spacerun: 'yes'"></SPAN></DIV>