Suricata

Between runs the only thing that I changed in suricata.yaml was from

detect-engine:
  - profile: high

to

detect-engine:
  - profile: medium

in both cases using - sgh-mpm-context: full :

detect-engine:
  - profile: high
  - custom-values:
      toclient-src-groups: 4
      toclient-dst-groups: 4
      toclient-sp-groups: 4
      toclient-dp-groups: 6
      toserver-src-groups: 4
      toserver-dst-groups: 8
      toserver-sp-groups: 4
      toserver-dp-groups: 30
  - sgh-mpm-context: full

detect-engine:
  - profile: medium
  - custom-values:
      toclient-src-groups: 4
      toclient-dst-groups: 4
      toclient-sp-groups: 4
      toclient-dp-groups: 6
      toserver-src-groups: 4
      toserver-dst-groups: 8
      toserver-sp-groups: 4
      toserver-dp-groups: 30
  - sgh-mpm-context: full

I can consistently reproduce the following -
with profile medium Suricata consumes 10G RAM more at startup as compared to profile high.
(with the very same set up)

It seems really strange that medium consumes a third more memory than high....

Some Suricata related info

suricata --build-info
This is Suricata version 2.0dev (rev 7e8f80b)
Features: PCAP_SET_BUFF LIBPCAP_VERSION_MAJOR=1 PF_RING AF_PACKET HAVE_PACKET_FANOUT LIBCAP_NG LIBNET1.1 HAVE_HTP_URI_NORMALIZE_HOOK HAVE_NSS HAVE_LIBJANSSON 
SIMD support: SSE_4_2 SSE_4_1 SSE_3 
Atomic intrisics: 1 2 4 8 16 byte(s)
64-bits, Little-endian architecture
GCC version 4.6.3, C version 199901
compiled with -fstack-protector
compiled with _FORTIFY_SOURCE=2
L1 cache line size (CLS)=64
compiled with LibHTP v0.5.11, linked against LibHTP v0.5.11
Suricata Configuration:
  AF_PACKET support:                       yes
  PF_RING support:                         yes
  NFQueue support:                         no
  IPFW support:                            no
  DAG enabled:                             no
  Napatech enabled:                        no
  Unix socket enabled:                     yes
  Detection enabled:                       yes

  libnss support:                          yes
  libnspr support:                         yes
  libjansson support:                      yes
  Prelude support:                         no
  PCRE jit:                                no
  libluajit:                               no
  libgeoip:                                no
  Non-bundled htp:                         no
  Old barnyard2 support:                   no
  CUDA enabled:                            no

  Suricatasc install:                      yes

  Unit tests enabled:                      no
  Debug output enabled:                    no
  Debug validation enabled:                no
  Profiling enabled:                       no
  Profiling locks enabled:                 no
  Coccinelle / spatch:                     yes

Generic build parameters:
  Installation prefix (--prefix):          /usr/local
  Configuration directory (--sysconfdir):  /usr/local/etc/suricata/
  Log directory (--localstatedir) :        /usr/local/var/log/suricata/

  Host:                                    x86_64-unknown-linux-gnu
  GCC binary:                              gcc
  GCC Protect enabled:                     no
  GCC march native enabled:                yes
  GCC Profile enabled:                     no