[squid-users] Long delays with TLS

Alex Rousskov

2018-09-13 19:46:04 UTC

Post by James Moe
Hello,
squid 4.0.23
linux 4.12.14-lp150.12.7-default x86_64
We have been seeing frequent, but not consistent, delays when proxying
TLS requests while browsing. By disabling the proxy, those delays
stopped occurring.

FYI: Your Squid is not configured to treat TLS specially. In that
configuration, your Squid does not know anything about TLS -- TLS
traffic is just opaque bytes to your Squid, hidden inside HTTP CONNECT
tunnels.

Post by James Moe
I can see no obvious hint in either the access or cache logs.
Where should I look to find what is causing the delay?

I would start by upgrading to the latest Squid v4 and then check for DNS
delays. DNS is used by both regular HTTP traffic and CONNECT tunnels
(carrying TLS bytes) so it may not fit your problem description
perfectly, but DNS delays are easier to check for than other suspects.
You can log DNS-related response times (%dt) and/or capture DNS traffic
to and from your Squid.

HTH,

Alex.

Post by James Moe
----[ conf ]----
acl manager_admin src 192.168.69.115
#
# acl localnet src fc00::/7
# acl localnet src fe80::/10
#
acl SSL_ports port 443
acl SSL_ports port 631
#
# Jumpline cPanel ports
acl SSL_ports port 2083
acl SSL_ports port 2096
#
# sma-nas-02, cgatePro, webadmin
acl SSL_ports port 5000
acl SSL_ports port 5001
acl SSL_ports port 9010
acl SSL_ports port 9100
acl SSL_ports port 10000
#
acl Safe_ports port 80
acl Safe_ports port 21
acl Safe_ports port 443
acl Safe_ports port 563
acl Safe_ports port 631
acl Safe_ports port 70
acl Safe_ports port 210
acl Safe_ports port 1025-65535
acl Safe_ports port 280
acl Safe_ports port 488
acl Safe_ports port 591
acl Safe_ports port 777
acl Safe_ports port 9100
#
acl CONNECT method CONNECT
acl localnet src 192.168.69.0/24
access_log /var/log/squid/access.log
#
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow manager_admin
http_access allow manager localhost
http_access deny manager
http_access allow localnet
http_access deny all
# Squid normally listens to port 3128
http_port 3128
cache_dir ufs /data01/var/cache/squid 51200 16 256
maximum_object_size 99999 KB
cache_mem 256 MB
coredump_dir /var/cache/squid
refresh_pattern ^ftp: 1440 20 10080
refresh_pattern ^gopher: 1440 0 1440
refresh_pattern -i (/cgi-bin/|\?) 0 0 0
refresh_pattern . 0 20 4320
cache_log /var/log/squid/cache.log
cache_replacement_policy lru
cache_store_log /var/log/squid/store.log
cache_swap_high 95
cache_swap_low 90
client_lifetime 1 days
connect_timeout 2 minutes
error_directory /usr/share/squid/errors/en
ftp_passive on
memory_replacement_policy lru
minimum_object_size 0 KB
----[ end ]----