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Questions tagged [latency]

Latency is the time period between a signal being sent and a signal being received

Latency is the time period between a signal being sent and a signal being received. In computer networking this can be the time between a sending of a packet and receiving of a packet.

To illustrate we can use the ping command:

PING google.be (173.194.66.94) 56(84) bytes of data.
64 bytes from google.be (173.194.66.94): icmp_req=1 ttl=47 time=76.6 ms
64 bytes from google.be (173.194.66.94): icmp_req=2 ttl=47 time=74.8 ms
64 bytes from google.be (173.194.66.94): icmp_req=3 ttl=47 time=79.6 ms

The latency here is 76.6 ms.

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How to apply `fq_codel` to balance traffic in multiple VLAN connections?

I have an Ubuntu server connected to multiple VLAN networks over a single physical 1 Gbps network port. The network connections are configured via /etc/network/interfaces like this: auto lo iface lo inet loopback auto eno1.395 iface eno1.395 inet…
Mikko Rantalainen
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Couchdb 3.1.1 increases disk latency gradually over weeks

I've been dealing with this issue for weeks now. I have the followin scenario: couchdb2.3.1-A <===> couchdb2.3.1-B <===> couchdb3.1.1-A <===> couchdb3.1.1-B where <===> represents two pull replications, one configured on each side. i.e: couchdb1…
Roberto Iglesias
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How is ping so low, lower than theoretical limit?

According to this article, we would expect a ping of at least 60 milliseconds for 10,000km of distance: Ireland is roughly 10,000km away from California, so this is the ping we would expect. I am pinging api.kraken.com from Ireland, which is…
David Callanan
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Latency of memory accesses via interconnectors

I'm trying to compare latencies of different node interconnects for a cluster. The goal is to minimize the memory access latency. I have obtained some benchmarks regarding one of the hardware implementations of NUMA architecture with many CPUs. This…
Piotr M
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What Might Change With a Debian Server Restart?

My server restarted three weeks ago, and ever since then, we have had some issues, such as a much slower TTFB when accessing the website. It went from less than a second to now more than 5 seconds. I tried to check the etc/resolv.conf in case the…
EmL
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How do I find out which DNS is being used, or which is the optimal one to speed up website response

I have a server which hosts a website and also multiple API's. Lately when we try to access the website there is a delay that lasts a few seconds before actually loading. I have a good suspicion that this is due to some DNS setting. Is there a way…
EmL
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How to adjust TCP Window Size?

I asked a similar question before, but I believe I was not clear with the details. I'm basically having some problems with my server related to high latency between the server and the clients due to the geographical distance. And making a research,…
Efe Zaladin
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Troubleshooting low TCP transfer rate behind a router

I’m trying to debug a low tcp transfer rate on a host (“lowHost”). As a reference, i’m comparing it against a second host (“highHost”). I’m making two rate measurements: Downloading a big file using curl from a webserver. Using iperf lowHost goes…
Tomer
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How to priorize Zoom meetings on a fritz.box?

is there a way to configure the fritz box to priorize zoom calls? Of course I could configure the IP to have higher prio, but this is not solving the issue, that I want to have Zoom only to have real time priority and not a stupid windows update…
cilap
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High ping latency over direct Gigabit Ethernet link on Enterprise-class hardware

FINAL EDIT 7/7 Multiple cable, port, and device substitutions have narrowed this to the Comcast modem, and on all 8 of its Ethernet ports. Given, as the comments say, this is a closed device, and unlikely to get much real information, we may never…
BaseZen
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CL latency of unbuffered and registered RAM

So AFAIK, registered ram generally has a bit higher latency as going through the registers adds (usually one?) cycle. If I have two dimms of ecc ram, one registered and one unbuffered, and both say in their specs for example CL19, is that added…
matthias_buehlmann
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iptables tool to measure latency instead of bandwidth

I'm trying to measure the latency of having a lot of iptables rules. I tried to use iperf but I think that bandwidth is not what i want. Any help with this?
PRVS
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If my database has to stay in one region, is there much point distributing my API across several?

We currently have an API and database in Australia, and are attempting to reduce latency in other countries. Coming to grips with the CAP theorem for synchronized databases is probably a little out-of-scope at present, but we're looking into…
MitchEff
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App Engine high latency

Hi we have an static web page using Smarty, we want to migrate it from our private web server on Compute Engine to App Engine. We did made the migration but on App Engine we got a latency of 3 sec to load the pague and on the server on Compute…
Austral
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Delay on NFS mounts

My setup: 3 machines, 2 client, 1 server. The server is redhat 7.6, the clients are ubuntu server 18.04.2. The mount is a few dozen TB, the files placed on the clients are a few 100Gigs each. The behavior I'm seeing is as follows: A file gets placed…
KdgDev
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