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<p class="p1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">I’m running
</span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">BIND 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.9 (Extended Support Version) on RHEL 7 in a chroot jail.</span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As of late, at times running some rndc commands are causing my server to lock up. It’s usually an “rndc addzone” that triggers the issue. I’ll also mention that I have recently started signing some domains with DNSSEC, so I suspect it may
be somehow related.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Here is an example of a command that frequently triggers my issue, although it doesn’t trigger it every time.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">rndc addzone '"example.com" in external {type master; file "dnssec/example.com";key-directory "keys"; auto-dnssec maintain; inline-signing yes;};'<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">During these times, named will not respond to any rndc commands, nothing is logged to the bind logs (I’m running trace level 3 ), and will not answer queries. Everything seems just frozen in time. Waiting for a period of time, varying from
a few seconds to many minutes, the server picks back up again and operates normally. The following are my observations to this point.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">CPU and memory show as being fine.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">top - 17:57:37 up 33 min,</span></span><span class="apple-converted-space"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">3 users,</span></span><span class="apple-converted-space"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">load average: 0.00, 0.01, 0.05</span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">Tasks:<b> 125
</b>total,<b> </b></span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">2
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">running,<b> 123
</b>sleeping,<b> </b></span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">stopped,<b>
</b></span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">zombie</span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">%Cpu(s):</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0.2
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">us,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0.3
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">sy,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0.0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">ni,<b> 98.5
</b>id,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0.0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">wa,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0.0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">hi,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0.0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">si,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">1.0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">s</span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">KiB Mem :</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">1842956
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">total,<b>
</b></span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">439452
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">free,<b>
</b></span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">665760
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">used,<b>
</b></span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">737744
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">buff/cache</span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">KiB Swap:</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">8384508
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">total,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">8384508
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">free,</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">0
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">used.</span></span><span class="apple-converted-space"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></b></span><span class="s1"><b><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">1013652
</span></b></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">avail Mem</span></span><span class="apple-converted-space"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"> </span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Strace shows the following over and over again.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">strace -p 1156 -f<o:p></o:p></span></span></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></span></p>
<p class="p1"><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">[pid</span></span><span class="apple-converted-space"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">
</span></span><span class="s1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif">1159] futex(0x7fc1c15a307c, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 16657, {tv_sec=1659390139, tv_nsec=255860000}, 0xffffffff) = -1 ETIMEDOUT (Connection
timed out)</span></span><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="p1"><span style="font-size:12.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
<p class="MsoNormal">Any pointers here would be greatly appreciated. I’m about at my wits end with this one, and rebuilding this server on a newer build of RHEL or recompiling BIND is not a journey that I would like to take at the moment.<o:p></o:p></p>
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