This article explains the behaviour of nstraced process going high due to traceoptions configuration.

While running below command in the operational mode of SRX to check the CPU utilisation, it has been observed that the utilisation of RE CPU is high because of nstraced process.

show system processes extensive |except 0.00   
node0:
--------------------------------------------------------------------------
last pid: 58688;  load averages:  2.12,  2.56,  2.73  up 9+20:35:53    02:48:53
394 threads:   2 running, 333 sleeping, 59 waiting
CPU:  7.8% user,  0.2% nice, 22.7% system,  4.4% interrupt, 64.8% idle
Mem: 164M Active, 579M Inact, 532M Laundry, 389M Wired, 141M Buf, 270M Free
Swap: 1638M Total, 111M Used, 1527M Free, 6% Inuse

PID USERNAME    PRI NICE   SIZE    RES STATE    TIME    WCPU COMMAND
11996 root         52    0   717M  6948K select  27.3H  42.29% nstraced -----------> Utilising RE CPU
11 root        155 ki31     0B    16K RUN    153.6H  21.58% idle

The nstraced process is responsible for the traceoptions function in the Juniper devices. If the CPU utilisation by this process is high, check if there is any traceoptions configuration present in the configuration.

Delete the traceoptions configuration rather deactivating the configuration and check the CPU utilisation again using show system processes extensive | except 0.00 command.

Example traceoptions configuration, which can be seen in the device configuration:-

set security ike traceoptions flag all
set security ipsec traceoptions flag all
set security flow traceoptions flag basic-datapath

Note:- Traceoptions configuration is required only during the time of troubleshooting. Post troubleshooting, it is advised to delete this configuration to avoid the high RE CPU utilisation. It is safe to delete this configuration without any impact.