[knot-dns-users] Excessive memory usage - knot 2.6.5

Dear all, While trying to migrate or DNS to Knot I have noticed that a slave server with 2GB RAM is facing memory exhaustion. I am running 2.6.5-1+0~20180216080324.14+stretch~1.gbp257446. There is 141 zones having around 1MB in total. Knot is acting as pure slave server with minimal configuration. There is nearly 1.7GB of memory consumed by Knot on a freshly rebooted server: root@eira:/proc/397# cat status Name:   knotd Umask:  0007 State:  S (sleeping) Tgid:   397 Ngid:   0 Pid:    397 PPid:   1 TracerPid:      0 Uid:    108     108     108     108 Gid:    112     112     112     112 FDSize: 64 Groups: 112 NStgid: 397 NSpid:  397 NSpgid: 397 NSsid:  397 VmPeak: 24817520 kB VmSize: 24687160 kB VmLck:         0 kB VmPin:         0 kB VmHWM:   1743400 kB VmRSS:   1743272 kB RssAnon:         1737088 kB RssFile:            6184 kB RssShmem:              0 kB VmData:  1781668 kB VmStk:       132 kB VmExe:       516 kB VmLib:     11488 kB VmPTE:      3708 kB VmPMD:        32 kB VmSwap:        0 kB HugetlbPages:          0 kB Threads:        21 SigQ:   0/7929 SigPnd: 0000000000000000 ShdPnd: 0000000000000000 SigBlk: fffffffe7bfbbefc SigIgn: 0000000000000000 SigCgt: 0000000180007003 CapInh: 0000000000000000 CapPrm: 0000000000000000 CapEff: 0000000000000000 CapBnd: 0000003fffffffff CapAmb: 0000000000000000 Seccomp:        0 Cpus_allowed:   f Cpus_allowed_list:      0-3 Mems_allowed:   00000000,00000001 Mems_allowed_list:      0 voluntary_ctxt_switches:        260 nonvoluntary_ctxt_switches:     316 root@eira:/proc/397# Config: server:     listen: 0.0.0.0@53     listen: ::@53     user: knot:knot log:   - target: syslog     any: info mod-rrl:   - id: rrl-10     rate-limit: 10    # Allow 200 resp/s for each flow     slip: 2           # Every other response slips mod-stats:   - id: custom     edns-presence: on     query-type: on     request-protocol: on     server-operation: on     request-bytes: on     response-bytes: on     edns-presence: on     flag-presence: on     response-code: on     reply-nodata: on     query-type: on     query-size: on     reply-size: on template:   - id: default     storage: "/var/lib/knot"     module: mod-rrl/rrl-10     module: mod-stats/custom     acl: [allowed_transfer]     disable-any: on     master: idunn I was pretty sure that a VM with 2GB RAM is enough for my setup :-) BR Ales