i want to use ntp.nict.jp server for ntp in my linux machine .
When i am configuring this server am getting the following ntp status :
[root#machine~]# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
ntp-a2.nict.go. .INIT. 16 u - 64 0 0.000 0.000 0.000
What i could see is that the domain ntp.nict.jp is load balanced to different domains
ntp-b3.nict.go.jp(133.243.238.164)
ntp-a3.nict.go.jp(133.243.238.244)
ntp-b2.nict.go.jp(133.243.238.163)
ntp-a2.nict.go.jp(133.243.238.243)
and if i am configuring any of the domains in the above list , the ntp works fine .
i wish to configure the entire servers under ntp.nict.jp for ntp.
How can i do this ?
You can use the "pool" command in the ntp.conf file as follows.
pool ntp.nict.jp iburst
Related
Most chrony server configurations I've found so far are about commenting out and setting the allow directive.
I'd like several servers in my network to be synchronized to one of my 2 dedicated chrony NTP servers, even if there's no Internet, and when each chronyd is not able to synchronize to any of X.pl.pool.ntp.org servers.
According to man, local stratum directive allows chrony to serve time 'even if not synchronized to a time source' - I'm wondering if it works in the following way: as long as chronyd is able to sync to one of the X.pl.pool.ntp.org servers, everything is fine; when chronyd is not able to sync to any external source, then it still serves as a valid NTP server for the local clients thanks to local stratum directive - am I right? Isn't it like telling the clients that chrony is always healthy no matter the Internet connection status thus you can always sync to it?
Question 1: should I comment out local stratum 10 to meet my requirements?
Question 2: I'm also considering using orphan mode on my NTP servers in the following way: local stratum 10 orphan
As far as I understand, it works in the following way: let's assume my NTP servers lose connections to all X.pl.pool.ntp.org servers (I configured them to pool the same external sources) - now - thanks to local stratum 10 orphan, the clients will always sync to the server with the lowest Reference ID first (we assume my production servers are set to poll only my local NTP servers) - am I right about it?
Regards,
I am a bit new to postgresql db. I have done a setup over Azure Cloud for my PostgreSQL DB.
It's Ubuntu 18.04 LTS (4vCPU, 8GB RAM) machine with PostgreSQL 9.6 version.
The problem that occurs is when the connection to the PostgreSQL DB stays idle for some time let's say 2 to 10 minutes then the connection to the db does not respond such that it doesn't fulfill the request and keep processing the query.
Same goes with my JAVA Spring-boot Application. The connection doesn't respond and the query keep processing.
This happens randomly such that the timing is not traceable sometimes it happens in 2 minutes, sometimes in 10 minutes & sometimes don't.
I have tried with PostgreSQL Configuration file parameters. I have tried:
tcp_keepalive_idle, tcp_keepalive_interval, tcp_keepalive_count.
Also statement_timeout & session_timeout parameters but it doesn't change anyway.
Any suggestion or help would be appreciable.
Thank You
If you are setting up PostgreSQL DB connection on Azure VM you have to be aware that there are Unbound and Outbound connections timeouts . According to
https://learn.microsoft.com/en-us/azure/load-balancer/load-balancer-outbound-connections#idletimeout ,Outbound connections have a 4-minute idle timeout. This timeout is not adjustable. For inbound timeou there is an option to change in on Azure Portal.
We run into similar issue and were able to resolve it on client side. We changed Spring-boot default Hikari configuration as follow:
hikari:
connection-timeout: 20000
validation-timeout: 20000
idle-timeout: 30000
max-lifetime: 40000
minimum-idle: 1
maximum-pool-size: 3
connection-test-query: SELECT 1
connection-init-sql: SELECT 1
I am running ntpd on a CentOS 6.9 server and my configuration for ntpd had been working without issue previously. Typically, it takes a little time but it will sync up with an higher stratum server after a period of time.
However, after I performed a kernel update last night, the server refuses to connect to any of them. It still shows everything besides the local peer as stratum 16.
remote refid st t when poll reach delay offset jitter
==============================================================================
69.164.198.192 .INIT. 16 u - 1024 0 0.000 0.000 0.000
198.55.111.50 .INIT. 16 u - 1024 0 0.000 0.000 0.000
216.218.254.202 .INIT. 16 u - 1024 0 0.000 0.000 0.000
162.210.111.4 .INIT. 16 u - 1024 0 0.000 0.000 0.000
I am using the following servers in the config.
server 0.north-america.pool.ntp.org
server 1.north-america.pool.ntp.org
server 2.north-america.pool.ntp.org
server 3.north-america.pool.ntp.org
ntpd is configured with these parameters.
restrict default noquery notrust nomodify notrap
I have tried stopping ntpd, doing a ntpdate -s/-u then starting ntpd again. It appears to adjust the clock at the time I run ntpdate, but refuses to sync up via the service. Everything just remains stratum 16 indefinitely.
Issue was due to peer server configuration. Removing that allowed it to sync up with upstream servers.
I have a stupid question, but I don't understand and i'd like to :)
I've set up a server mysrv and different client machines. The server is used as NTP server, and is configured with a Undisciplined Local Clock : with fudge 127.127.1.0 stratum 5
First question, if I well understand, my NTP server is now set as stratum 5 ?
Now on my clients, when I type a ntpq -p to check, they are synchronized so it's cool, but they see mysrv as stratum 6 (the column st of ntpq -p indicates 6) ... I was expecting 5...
Why ?
Thanx a lot
Your reasoning in the comment is correct. A server's stratum is X+1 where X is the stratum of the time source that the machine is synced to. Reference clocks, ie GPSDO, Rubidium, etc, are stratum 0. The time servers connected to these sources are stratum 1.
I am trying to setup a local NTP Server without Internet Connection.
Below is my ntp.conf on Server
# Server
server 127.127.1.0
fudge 127.127.1.0 stratum 5
broadcast 10.108.190.255
Below is my ntp.conf on Clients
# Clients
server 10.108.190.14
broadcastclient
but my clients are not sync with the server. Output to ntpq -p on Clients show that they are not taking time from the server, and server ip is show at stratum 16
Could any one please help in this issue.
The server should use its local clock as the source. A better set up is to use orphan mode for isolated networks which gives you fail-over. Check out the documentation:
http://www.eecis.udel.edu/~mills/ntp/html/orphan.html
You need to configure the clients with th e prefer keyword. ntpd tries its hardest not to honor local undisciplined clocks in order to prevent screwups.
server 10.108.190.14 prefer
For more information see: http://www.ntp.org/ntpfaq/NTP-s-config-adv.htm#AEN3658
This is all assuming that you have included the full and entire ntp.con and did not leave out any bits about restrict lines.
How about using chrony?
Steps
Install chrony in both your devices
sudo apt install chrony
Let's assume the server IP address 192.168.1.87 then client configuration (/etc/chrony/chrony.conf) as follows:
server 192.168.1.87 iburst
keyfile /etc/chrony/chrony.keys
driftfile /var/lib/chrony/chrony.drift
log tracking measurements statistics
logdir /var/log/chrony
Server configuration (/etc/chrony/chrony.conf), assume your client IP is 192.168.1.14
keyfile /etc/chrony/chrony.keys
driftfile /var/lib/chrony/chrony.drift
log tracking measurements statistics
logdir /var/log/chrony
local stratum 8
manual
allow 192.0.0.0/24
allow 192.168.1.14
Restart chrony in both computers
sudo systemctl stop chrony
sudo systemctl start chrony
5.1 Checking on the client-side,
sudo systemctl status chrony
`**output**:
июн 24 13:26:42 op-desktop systemd[1]: Starting chrony, an NTP client/server...
июн 24 13:26:42 op-desktop chronyd[9420]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SECHASH +SIGND +ASYNCDNS +IPV6 -DEBUG)
июн 24 13:26:42 op-desktop chronyd[9420]: Frequency -6.446 +/- 1.678 ppm read from /var/lib/chrony/chrony.drift
июн 24 13:26:43 op-desktop systemd[1]: Started chrony, an NTP client/server.
июн 24 13:26:49 op-desktop chronyd[9420]: Selected source 192.168.1.87`
5.1 chronyc tracking output:
Reference ID : C0A80157 (192.168.1.87)
Stratum : 9
Ref time (UTC) : Thu Jun 24 10:50:34 2021
System time : 0.000002018 seconds slow of NTP time
Last offset : -0.000000115 seconds
RMS offset : 0.017948076 seconds
Frequency : 5.491 ppm slow
Residual freq : +0.000 ppm
Skew : 0.726 ppm
Root delay : 0.002031475 seconds
Root dispersion : 0.000664742 seconds
Update interval : 65.2 seconds
Leap status : Normal