Seems like you have dhcp configuration on few ports which are not up. If dhcp is not required on those ports, please delete the dhcp on those interfaces and check if it resolves the issue.
By default system would have configured dhcp for ZTP on few interfaces. If the interface is down and there is dhcp traceoptions configured, you will see these continuous log messages.
Ex: For QFX following default configuration will be enabled for Zero Touch Provisioning.
If any of the interface em1.0 /irb.0 / vme.0 is down then the error messages "DH_SVC_SENDMSG_FAILURE" appear in the log.
set system processes dhcp-service traceoptions file dhcp_logfile
set system processes dhcp-service traceoptions file size 10m
set system processes dhcp-service traceoptions level all
set system processes dhcp-service traceoptions flag all
set interfaces em1 unit 0 family inet dhcp vendor-id Juniper-qfx5100-96s-8q
set interfaces irb unit 0 family inet dhcp vendor-id Juniper-qfx5100-96s-8q
set interfaces vme unit 0 family inet dhcp vendor-id Juniper-qfx5100-96s-8q
In above example if dhcp on vme is not required and that interface is down then "delete interfaces vme unit 0 family inet dhcp" would stop the log messages "DH_SVC_SENDMSG_FAILURE" .