[SOLVED] Java DNS caching process, high CPU load

[JayM]

Java keeps running every few hours doing some process or other even when I don't have any Java apps running, and it's eating up around 65% of my CPU. Add that used by Firefox, MX, Xfce, etc. and I'm up at around 100% utilization whenever this Java thing is running, and also making the CPU's temperature higher. Does anyone know what Java is doing and how I can either get it to stop or at lease be a lot more nice?

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System:    Host: mx Kernel: 4.9.0-9-686-pae i686 bits: 32 compiler: gcc v: 6.3.0 
           Desktop: Xfce 4.12.3 Distro: MX-18.3_386 Continuum May 26  2019 
           base: Debian GNU/Linux 9 (stretch) 
Machine:   Type: Other-vm? System: AVERATEC product: N1130 v: N/A serial: <filter> 
           Mobo: AVERATEC model: N1130 serial: <filter> BIOS: Phoenix 
           v: NAPA0001.86C.0056.D.0907311757 date: 07/31/09 
Battery:   ID-1: BAT0 charge: 0 Wh condition: 0/2.1 Wh model: AVERATEC N1130 status: Unknown 
CPU:       Topology: Single Core model: Intel Atom N270 bits: 32 type: MT arch: Bonnell rev: 2 
           L2 cache: 512 KiB 
           flags: nx pae sse sse2 sse3 ssse3 bogomips: 6384 
           Speed: 1600 MHz min/max: 800/1600 MHz Core speeds (MHz): 1: 1600 2: 1600 
Graphics:  Device-1: Intel Mobile 945GSE Express Integrated Graphics driver: i915 v: kernel 
           bus ID: 00:02.0 
           Display: x11 server: X.Org 1.19.2 driver: intel unloaded: fbdev,modesetting,vesa 
           resolution: 1024x600~60Hz, 1280x1024~60Hz 
           OpenGL: renderer: Mesa DRI Intel 945GME x86/MMX/SSE2 v: 1.4 Mesa 18.2.6 
           direct render: Yes 
Audio:     Device-1: Intel NM10/ICH7 Family High Definition Audio driver: snd_hda_intel 
           v: kernel bus ID: 00:1b.0 
           Sound Server: ALSA v: k4.9.0-9-686-pae 
Network:   Device-1: Ralink RT3090 Wireless 802.11n 1T/1R PCIe driver: rt2800pci v: 2.3.0 
           port: 18e0 bus ID: 02:00.0 
           IF: wlan0 state: down mac: <filter> 
           Device-2: Realtek RTL8101/2/6E PCI Express Fast/Gigabit Ethernet driver: r8169 
           v: 2.3LK-NAPI port: 2000 bus ID: 04:00.0 
           IF: eth0 state: up speed: 100 Mbps duplex: full mac: <filter> 
Drives:    Local Storage: total: 111.79 GiB used: 58.01 GiB (51.9%) 
           ID-1: /dev/sda vendor: Gigabyte model: GP-GSTFS31120GNTD size: 111.79 GiB temp: 33 C 
Partition: ID-1: / size: 107.04 GiB used: 57.73 GiB (53.9%) fs: ext4 dev: /dev/dm-0 
           ID-2: /boot size: 487.9 MiB used: 270.2 MiB (55.4%) fs: ext4 dev: /dev/sda1 
           ID-3: swap-1 size: 2.00 GiB used: 17.0 MiB (0.8%) fs: swap dev: /dev/dm-1 
Sensors:   System Temperatures: cpu: 54.0 C mobo: 26.8 C 
           Fan Speeds (RPM): N/A 
Repos:     Active apt repos in: /etc/apt/sources.list.d/antix.list 
           1: deb http://iso.mxrepo.com/antix/stretch stretch main
           Active apt repos in: /etc/apt/sources.list.d/debian-stable-updates.list 
           1: deb http://ftp.hk.debian.org/debian/ stretch-updates main contrib non-free
           Active apt repos in: /etc/apt/sources.list.d/debian.list 
           1: deb http://ftp.hk.debian.org/debian/ stretch main contrib non-free
           2: deb http://security.debian.org/ stretch/updates main contrib non-free
           Active apt repos in: /etc/apt/sources.list.d/mx.list 
           1: deb https://mirror.pregi.net/mx-linux-packages/mx/repo/ stretch main non-free
           No active apt repos in: /etc/apt/sources.list.d/various.list 
Info:      Processes: 191 Uptime: 1h 29m Memory: 1.96 GiB used: 1007.4 MiB (50.1%) 
           Init: SysVinit runlevel: 5 Compilers: gcc: 6.3.0 Shell: bash v: 4.4.12 inxi: 3.0.33 

[JayM]

I found out that it's running some sort of DNS caching process, but I'm not sure why as I wasn't running anything Java-based all morning, just Firefox. I'm still trying to figure out what triggers this to run and how I can keep it from using up my entire CPU when it does. Supposedly the TTL=0 is telling it to immediately discard and not save its caching results so I don't understand why it even needs to run. All it seems to be doing is slowing down my computer and serving no purpose that I can see.

[JayM]

I may have solved it. I vaguely recalled having a slightly similar problem when using PCLinuxOS on a 32-bit laptop several years ago and that it was due to Avahi and/or some local file indexing service that PCLOS had, so I uninstalled avahi-daemon in MX and rebooted. Monitoring my task manager, I saw that java process spawn for just a fraction of a second then terminate and I haven't seen it come back so far. My CPU is throttling again and running at 30%-50% load with Firefox open with three active tabs, and also Task Manager still running. I want to watch it for several hours though, on the chance that java has merely finished its DNS caching for the day. If it still doesn't run and bog down my computer by tomorrow I'll mark this as solved.

[JayM]

Well, that didn't fix it. The java DNS caching just started again.

OK, now I think I have it. I found a Java app that was autostarting and running in the background. Back to monitoring the situation.

Edit: that was it.