<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:odc="urn:schemas-microsoft-com:office:odc" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:rtc="http://microsoft.com/officenet/conferencing" xmlns:D="DAV:" xmlns:Repl="http://schemas.microsoft.com/repl/" xmlns:mt="http://schemas.microsoft.com/sharepoint/soap/meetings/" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:ppda="http://www.passport.com/NameSpace.xsd" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sub="http://schemas.microsoft.com/sharepoint/soap/2002/1/alerts/" xmlns:ec="http://www.w3.org/2001/04/xmlenc#" xmlns:sp="http://schemas.microsoft.com/sharepoint/" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcs="http://schemas.microsoft.com/data/udc/soap" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:udcp2p="http://schemas.microsoft.com/data/udc/parttopart" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" xmlns:dsss="http://schemas.microsoft.com/office/2006/digsig-setup" xmlns:dssi="http://schemas.microsoft.com/office/2006/digsig" xmlns:mdssi="http://schemas.openxmlformats.org/package/2006/digital-signature" xmlns:mver="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns:mrels="http://schemas.openxmlformats.org/package/2006/relationships" xmlns:spwp="http://microsoft.com/sharepoint/webpartpages" xmlns:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:pptsl="http://schemas.microsoft.com/sharepoint/soap/SlideLibrary/" xmlns:spsl="http://microsoft.com/webservices/SharePointPortalServer/PublishedLinksService" xmlns:Z="urn:schemas-microsoft-com:" xmlns:st="" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=iso-8859-1"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Texte brut Car";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.5pt;
font-family:Consolas;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.TextebrutCar
{mso-style-name:"Texte brut Car";
mso-style-priority:99;
mso-style-link:"Texte brut";
font-family:Consolas;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:12.0pt'>Hi,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>I found the timeout issue. It turns out that the keep_alive is not generated by Syslog-NG but by the OS. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>I adjusted the following values:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>tcp_keepalive_time<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>tcp_keepalive_intvl<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>tcp_keepalive_probes<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>First in the live Kernel with the command :<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>sysctl -w net.ipv4.tcp_keepalive_time=180 net.ipv4.tcp_keepalive_intvl=180 net.ipv4.tcp_keepalive_probes=9<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>Then I made it permanent with adding to /etc/sysctl.conf:<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='font-size:12.0pt'>cat >>/etc/sysctl.conf <<EOF<o:p></o:p></span></p><p class=MsoNormal><span lang=FR-CA style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span lang=FR-CA style='font-size:12.0pt'>#<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'># Keepalive parameters for the syslog-ng<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>#<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>net.ipv4.tcp_keepalive_time = 180<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>net.ipv4.tcp_keepalive_intvl = 180<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>net.ipv4.tcp_keepalive_probes = 9<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>EOF<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>You can verify your work is done with the following command:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>sysctl net.ipv4.tcp_keepalive_time net.ipv4.tcp_keepalive_intvl net.ipv4.tcp_keepalive_probes<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><i><span style='font-size:12.0pt'>net.ipv4.tcp_keepalive_time = 180<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='font-size:12.0pt'>net.ipv4.tcp_keepalive_intvl = 180<o:p></o:p></span></i></p><p class=MsoNormal><i><span style='font-size:12.0pt'>net.ipv4.tcp_keepalive_probes = 9<o:p></o:p></span></i></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>I found the information from this URL: </span><span lang=EN-US><a href="http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/usingkeepalive.html">http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/usingkeepalive.html</a><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Maybe it could be mentioned in the documentation that the so_keep-alive option can be tweaked at the kernel level. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt'><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>------------------------------<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>Message: 8<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Date: Tue, 3 Jan 2012 17:46:06 -0500<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>From: Andr? Larose <<a href="mailto:andre.larose@telus.com">andre.larose@telus.com</a>><o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Subject: [syslog-ng] Syslog-ng 3.2 connection timeout with firewall<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>To: "<a href="mailto:syslog-ng@lists.balabit.hu">syslog-ng@lists.balabit.hu</a>" <<a href="mailto:syslog-ng@lists.balabit.hu">syslog-ng@lists.balabit.hu</a>><o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Message-ID:<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US> <<a href="mailto:BDB004F99074254BBCEE3AB94F31FDF5435439F706@WP40066.corp.ads">BDB004F99074254BBCEE3AB94F31FDF5435439F706@WP40066.corp.ads</a>><o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US>Content-Type: text/plain; charset="iso-8859-1"<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>Hi,<o:p></o:p></span></p><p class=MsoPlainText><span lang=EN-US><o:p> </o:p></span></p><p class=MsoPlainText><span lang=EN-US>I have two syslog-ng 3.2, one client and one server. The two are separated by a firewall and a load balancer. I noticed that after some inactivity I was not able to receive logs from my client. So I started some tcpdump on both servers to check the traffic.