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</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Hi.<o:p></o:p></p><p class=MsoNormal>I was considering using pgpool in our environment, but I don’t know if it is the best idea. I would appreciate some suggestions, pros, cons of the solution using pgpool. Or is there another way how to do it?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We have 2 technical centers TC1 and TC2. In each runs postgres server. Technical centers are connected with WAN link. <o:p></o:p></p><p class=MsoNormal>Clients are connecting through postgres JDBC driver to the TC1. If TC1 goes down JDBC driver will connect to TC2 automatically. Each technical center has the IP address from other subnet.<o:p></o:p></p><p class=MsoNormal>We need to have replicated data from postgres in TC1 to postgres in TC2.<o:p></o:p></p><p class=MsoNormal>Moreover:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>TC1 can act as read-write server<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>TC2 can act as read server<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>after TC1 goes down TC2 should became read-write -> this FAIL-OVER should be automatic<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>-<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>FAIL-BACK procedure doesn’t have to be automatic… we can do it manually<o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>I know the fine way with manual fail-over can be postgres streaming replication from TC1 to TC2. However I expect the pgpool can add more control over automatic fail-over and better control for manual fail-back.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>My questions…<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>Is the aforementioned scenario possible to build using pgpool?<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>Can pgpool fail-over to the IP address from different subnet? I mean not providing virtual IP address but making TC2 as R/W.<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>If it is possible I will have more questions while building it </span><span style='font-family:Wingdings;mso-fareast-language:EN-GB'>J</span><span style='mso-fareast-language:EN-GB'><o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>Best regards,<o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-GB'>Michal Mistina<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>