Task #4594
open
systemd service files dependency corrections for nfd and associated daemons
80%
Description
The systemd service files currently in use for Ubuntu 16.04 do not correctly support stopping and restarting
daemons that are dependent on each other. For example when we do a stop of nfd:
systemctl stop nfd
nfd and all the dependent daemons should be stopped. Because it is misconfigured, nfd stops and restarts.
Also, when we try to start nfd:
systemctl start nfd
we would like all the associated daemons to start as well. This does not happen.
To fix this, the nfd.service file should contain this in its Unit section:
Wants=nlsr.service
Wants=nfd-autoreg.service
Wants=nfd-status-http-server.service
Wants=repo-ng.service
Wants=repo-ng2.service
Wants=ndnping.service
Wants=ndn-autoconfig-server.service
And each service listed above (nlsr, nfd-autoreg, nfd-status-http-server, repo-ng, repo-ng2, ndnping and ndn-autoconfig-server) should contain this in its Unit section:
Requires=nfd.service
After=nfd.service
Two of the service files should be corrected in the Package system: nfd-status-http-server.service and nfd-autoreg.service.
nfd-status-http-server.service is missing the Requires=nfd.service.
nfd-autoreg.service has Wants=nfd.service which should be replaced with Requires=nfd.service.
nlsr.service, repo-ng.service, ndnping.service and ndn-autoconfig-server.service are all correct.
repo-ng2.service is a second repo-ng that we set up on the Testbed and will need to be taken care of by the Testbed config scripts.
The nfd.service changes should also probably be taken care of by the Testbed config scripts since not alll
Ubuntu users of NFD will want to include all those daemons.
Updated by John DeHart over 6 years ago
Looks like what we really want is to have all the dependent services (nlsr, nfd-autoreg, ...) have this in their Unit section:
BindsTo=nfd.service
After=nfd.service
And this in their Install section:
WantedBy=nfd.service
Then the dependent services need to be re-enabled (systemctl enable nlsr.service ...)
The WantedBy will cause a 'want's symlink to be created for nfd.service.
With this we don't need to add anything to the nfd.service file.
So, there will be a change to all the dependent daemons .service files.
Updated by Davide Pesavento almost 6 years ago
- Description updated (diff)
- Category set to Ubuntu-PPA
- Status changed from New to In Progress
- Start date deleted (
04/26/2018) - % Done changed from 0 to 30
NFD commit f392b8ff44e6456aecc7374211ad60edb3380a13 vastly improves the existing systemd service files for nfd, nfd-autoreg, nfd-status-http-server, ndn-autoconfig-client, ndn-autoconfig-server, and moves them to the NFD repo. The PPA packages should be switched over to the new files.
Updated by Davide Pesavento almost 6 years ago
John DeHart wrote:
And each service listed above (nlsr, nfd-autoreg, nfd-status-http-server, repo-ng, repo-ng2, ndnping and ndn-autoconfig-server) should contain this in its Unit section:
Requires=nfd.service After=nfd.service
BindsTo= instead of Requires= is a better solution, as you already said in note-1 and I implemented in NFD commit f392b8ff44e6456aecc7374211ad60edb3380a13.
nfd-status-http-server.service is missing the
Requires=nfd.service.
No, nfd-status-http-server does not require NFD to be running in order to start, and can cope with NFD restarting or crashing just fine. The dependency is unnecessary.
nfd-autoreg.service has
Wants=nfd.servicewhich should be replaced withRequires=nfd.service.
Changed to BindsTo=nfd.service instead, as explained above.
Updated by Davide Pesavento almost 6 years ago
John DeHart wrote:
And this in their Install section:
WantedBy=nfd.service
Then the dependent services need to be re-enabled (systemctl enable nlsr.service ...)
The WantedBy will cause a 'want's symlink to be created for nfd.service.
With this we don't need to add anything to the nfd.service file.
This is a much better approach than using Wants=... in nfd.service (which would have been a nonstarter in my opinion). I'm still not 100% comfortable with this though, nfd does not really need any other services, and in many cases it's run alone. But I can accept adding the WantedBy= if you say that it greatly simplifies the management of multiple NDN services that run on top of NFD.
Note that you can achieve the same effect by adding a symlink in nfd.service.wants/ for each "wanted" service, as documented in systemd.unit(5). You can do this locally on your machines if you want this behavior.
Updated by Davide Pesavento almost 6 years ago
- % Done changed from 30 to 40
https://gerrit.named-data.net/c/NFD/+/5122 adds WantedBy=nfd.service
Updated by Davide Pesavento almost 6 years ago
- % Done changed from 40 to 50
https://gerrit.named-data.net/c/ndn-tools/+/5125 adds ndn-ping-server.service to ndn-tools repo, with proper BindsTo= and WantedBy= directives
Updated by Davide Pesavento almost 6 years ago
- % Done changed from 50 to 60
Updated by Davide Pesavento almost 6 years ago
- % Done changed from 60 to 70
Updated by Davide Pesavento almost 6 years ago
- % Done changed from 70 to 80
https://gerrit.named-data.net/c/NLSR/+/5197 This concludes the set of patches adding improved systemd unit files to the various repositories, unless I missed something.
The remaining 20% of this task is changing the PPA packages to install these new unit files.