Bug 1027222

Summary: remote service management: 20 parallel requests fails
Product: Red Hat Enterprise Linux 7 Reporter: Petr Sklenar <psklenar>
Component: opensshAssignee: Petr Lautrbach <plautrba>
Status: CLOSED NOTABUG QA Contact: BaseOS QE Security Team <qe-baseos-security>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.0CC: lnykryn, systemd-maint-list
Target Milestone: rc   
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Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2013-11-11 14:13:25 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Petr Sklenar 2013-11-06 11:54:28 UTC
Description of problem:
remote service management: 20 parallel requests fails

Version-Release number of selected component (if applicable):
systemd-207-5.el7.x86_64

How reproducible:
always

Steps to Reproduce:
1.  for i in `seq 1 20`; do echo "$(systemctl --host root list-unit-files)" > ${i}.log & done

Actual results:
10 process in the background passes
20 not with an errors:
Failed to get D-Bus connection: Connection terminated during authentication.
ssh_exchange_identification: read: Connection reset by peer

Expected results:
it passes, or docs with the limit?

Additional info:

Comment 3 Lukáš Nykrýn 2013-11-11 13:56:21 UTC
I don't think that this is matter of systemd. 

for i in `seq 1 20`; do echo "$(ssh 192.168.122.223 echo hello)" > ${i}.log & done

ssh_exchange_identification: read: Connection reset by peer
ssh_exchange_identification: read: Connection reset by peer

Comment 4 Petr Lautrbach 2013-11-11 14:13:25 UTC
This is an expected behaviour. sshd is configured to use the random early drop  of unauthenticated connections, see MaxStartups is sshd_config(5). This value is set to 10:30:60 by default. So the first 10 new connections go in and every other connection has 30% chance to be dropped because the first 10 haven't been authenticated yet.