Alert Type

PSN - Product Support Notification

Product Affected

MX EX PTX vMX

Alert Description

In a deployment using Message Queue Telemetry Transport (MQTT), a system can experience memory leakage (about 4k memory leakage every 30 seconds).  If the "mosquitto-nossl" runs for a long time, this leads to it using high memory and can indirectly impact other running processes.

The mosquitto-nossl process is used to back the MQTT states and is enabled by default. 
The mosquitto-nossl process might have memory leak as follows. If there is no mosquitto-nossl process, the device is not affected by this issue. 

user@device> show system processes extensive | match mos   
Nov 27 20:19:33
19910 daemon      1  20    0 22740K  1864K select  1   0:00   0.00% mosquitto-nossl
20622 daemon      1  20    0 22740K  2596K select  1   0:00   0.00% mosquitto-nossl
20624 daemon      1  20    0 22740K  2596K select  0   0:00   0.00% mosquitto-nossl

user@device> show system processes extensive | match mos   
Nov 27 20:26:09
20622 daemon      1  20    0 22740K  2648K select  0   0:00   0.00% mosquitto-nossl
20624 daemon      1  20    0 22740K  2648K select  1   0:00   0.00% mosquitto-nossl
19910 daemon      1  20    0 22740K  1908K select  1   0:00   0.00% mosquitto-nossl

The error messages might be seen as follows: 

  rpd[14910]: RPD_KRT_Q_RETRIES: route add: Resource temporarily unavailable
  kernel: rt_pfe_veto: Severe memory pressure, low-free-pages is below threshold. Op 1 err 12, rtsm_id 5:-1, msg type 2
  kernel: rt_pfe_veto: free page threshold = (15519) number of pages free = (39444) number of pages on buffer cache queue = (0) curproc = rpd
   

Solution

This issue is being tracked via PR1324531. Customers running the affected software are encouraged to evaluate and deploy Junos Software with the fix.
The following is the list of affected software:

  • 16.2R1 or later​ ​
    • fixed in 16.2R2-S7 or later, and 16.2R3
  • 17.1R1 or later
    • fixed in 17.1R2-S7 or later, and 17.1R3
  • 17.2R1 or later
    • fixed in 17.2R2-S6 or later, and 17.2R3
  • 17.3R1 or later
    • fixed in 17.3R2-S3 or later, and 17.3R3
  • 17.4R1 or later
    • fixed in 17.4R1-S1 or later, 17.4R2 or later
  • Does not affect Junos 18.x or later releases

If you can not upgrade Junos software, there is a workaround available. Please check PR1324531 for the workaround and current information.

Modification History

First publication 2019-08-02

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