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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal>We are using RabbitMQ (version: 3.1.3) in federation mode on two different machines. We are using &#8220;rabbitmq-c&#8221; client library to publish messages to upstream broker, and right now we are not using confirm method or message persistence. But we want to achieve message reliability i.e. we don&#8217;t want to lose any messages. To achieve this, I am planning to use confirm method on publisher. I have following questions regarding the same:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol'><span style='mso-list:Ignore'>&middot;<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><![endif]>If I get the confirmation acknowledgement, what does it mean? Is it message successfully delivered to &#8220;upstream queue&#8221; or &#8220;downstream exchange&#8221;?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol'><span style='mso-list:Ignore'>&middot;<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><![endif]>If it guarantees delivery to &#8220;downstream exchange&#8221;, then do we need to use message persistence?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol'><span style='mso-list:Ignore'>&middot;<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><![endif]>If confirmation means delivery to upstream queue, then, I think, it makes sense to use message persistence, right? If the upstream broker crashes, then without message persistence, messages in upstream queue will be lost, right?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol'><span style='mso-list:Ignore'>&middot;<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><![endif]>How does message persistence work? How long messages are persisted on disk? Are they removed from disk when the consumer sends the acknowledgement?<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-family:Symbol'><span style='mso-list:Ignore'>&middot;<span style='font:7.0pt "Times New Roman"'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><![endif]>Or is there any other way to achieve message reliability? Any improvements or suggestions?<o:p></o:p></p><p class=MsoNormal><o:p>&nbsp;</o:p></p><p class=MsoNormal>Thanks in Advance,<o:p></o:p></p><p class=MsoNormal>Punit<o:p></o:p></p></div></body></html>