Radosław pointed another bug https://bugs.launchpad.net/keystonemiddleware/+bug/1883659 referring to the same fix https://review.opendev.org/#/c/742193/ Regarding to the fix, The comment says "This flag is off by default for backwards compatibility.". But I see this flag is on by default in current code. That's how it causes issues. This fix changes the default value from on to off. It does break backwards compatibility. To keep Keystone working as the old way, along with this fix, this flag has to be explicitly set to true in keystone.conf. For neutron-server and nova-api, it's good to leave this flag off by default. Am I correct? Thanks! Tony
-----Original Message----- From: Herve Beraud <hberaud@redhat.com> Sent: Monday, September 14, 2020 8:27 AM To: Tony Liu <tonyliu0592@hotmail.com> Cc: openstack-discuss <openstack-discuss@lists.openstack.org> Subject: Re: memchached connections
Hello,
python-memcached badly handles connections during a flush on reconnect and so connections can grow up exponentially [1].
I don't know if it is the same issue that you faced but it could be a track to follow.
On oslo.cache a fix has been submitted but it is not yet merged [2].
[1] https://bugs.launchpad.net/oslo.cache/+bug/1888394 [2] https://review.opendev.org/#/c/742193/
Le ven. 11 sept. 2020 à 23:29, Tony Liu <tonyliu0592@hotmail.com <mailto:tonyliu0592@hotmail.com> > a écrit :
Hi,
Is there any guidance or experiences to estimate the number of memcached connections?
Here is memcached connection on one of the 3 controllers. Connection number is the total established connections to all 3 memcached nodes.
Node 1: 10 Keystone workers have 62 connections. 11 Nova API workers have 37 connections. 6 Neutron server works have 4304 connections. 1 memcached has 4973 connections.
Node 2: 10 Keystone workers have 62 connections. 11 Nova API workers have 30 connections. 6 Neutron server works have 3703 connections. 1 memcached has 4973 connections.
Node 3: 10 Keystone workers have 54 connections. 11 Nova API workers have 15 connections. 6 Neutron server works have 6541 connections. 1 memcached has 4973 connections.
Before I increase the connection limit for memcached, I'd like to understand if all the above is expected?
How Neutron server and memcached take so many connections?
Any elaboration is appreciated.
BTW, the problem leading me here is memcached connection timeout, which results all services depending on memcached stop working properly.
Thanks! Tony
--
Hervé Beraud Senior Software Engineer
Red Hat - Openstack Oslo irc: hberaud -----BEGIN PGP SIGNATURE-----
wsFcBAABCAAQBQJb4AwCCRAHwXRBNkGNegAALSkQAHrotwCiL3VMwDR0vcja10Q+ Kf31yCutl5bAlS7tOKpPQ9XN4oC0ZSThyNNFVrg8ail0SczHXsC4rOrsPblgGRN+ RQLoCm2eO1AkB0ubCYLaq0XqSaO+Uk81QxAPkyPCEGT6SRxXr2lhADK0T86kBnMP F8RvGolu3EFjlqCVgeOZaR51PqwUlEhZXZuuNKrWZXg/oRiY4811GmnvzmUhgK5G 5+f8mUg74hfjDbR2VhjTeaLKp0PhskjOIKY3vqHXofLuaqFDD+WrAy/NgDGvN22g glGfj472T3xyHnUzM8ILgAGSghfzZF5Skj2qEeci9cB6K3Hm3osj+PbvfsXE/7Kw m/xtm+FjnaywZEv54uCmVIzQsRIm1qJscu20Qw6Q0UiPpDFqD7O6tWSRKdX11UTZ hwVQTMh9AKQDBEh2W9nnFi9kzSSNu4OQ1dRMcYHWfd9BEkccezxHwUM4Xyov5Fe0 qnbfzTB1tYkjU78loMWFaLa00ftSxP/DtQ//iYVyfVNfcCwfDszXLOqlkvGmY1/Y F1ON0ONekDZkGJsDoS6QdiUSn8RZ2mHArGEWMV00EV5DCIbCXRvywXV43ckx8Z+3 B8qUJhBqJ8RS2F+vTs3DTaXqcktgJ4UkhYC2c1gImcPRyGrK9VY0sCT+1iA+wp/O v6rDpkeNksZ9fFSyoY2o =ECSj -----END PGP SIGNATURE-----