How to read "isi statistics" outputs?

Does anybody know why "# isi statistics query --stats node.ifs.ops.in.rate" output is very different from that of "# isi statistics system --oprates --nodes"?

Both commands check imput "ops/s" of Isilon but it seems to me the two commands provide different information from the same Isilon.

# isi version

Isilon OneFS v7.2.1.4 B_MR_7_2_1_4_078(RELEASE): 0x70201500040004E:Sat Sep  3 10:29:28 GMT 2016    root@sea-build7-101:/b/mnt/obj/b/mnt/src/sys/IQ.amd64.release   clang version 3.3 (tags/RELEASE_33/final)

# isi statistics describe --stats node.ifs.ops.in.rate

Stat key             => Description

node.ifs.ops.in.rate => Operation input rate to /ifs on the node (ops/sec)

# isi statistics describe --stats node.ifs.ops.out.rate

Stat key              => Description

node.ifs.ops.out.rate => Operation output rate to /ifs on the node (ops/sec)

# isi statistics query --stats node.ifs.ops.in.rate  <= 1.

  NodeID node.ifs.ops.in.rate

       3              51924.4

average              51924.4

# isi statistics query --stats node.ifs.ops.out.rate

  NodeID node.ifs.ops.out.rate

       3               57626.8

average               57626.8

# isi statistics system --oprates --nodes  <=2.

Node   CPU   SMB   FTP  HTTP ISCSI   NFS  HDFS Total NetIn NetOut DiskIn DiskOut

  LNN %Used Ops/s Ops/s Ops/s Ops/s Ops/s Ops/s Ops/s Pkt/s  Pkt/s  Ops/s   Ops/s

  All  24.3   0.0   0.0   0.0   0.0   0.0   0.0   0.0  36.6    8.0    13K     0.0

    2  22.5   0.0   0.0   0.0   0.0   0.0   0.0   0.0  11.8    0.2   5.1K     0.0

    3  23.4   0.0   0.0   0.0   0.0   0.0   0.0   0.0  15.4    7.4   4.4K     0.0

    4  27.1   0.0   0.0   0.0   0.0   0.0   0.0   0.0   9.4    0.4   3.9K     0.0

In above example,  1. "# isi statistics query --stats node.ifs.ops.in.rate" shows several ops/sec counts but 2. "# isi statistics system --oprates --nodes" indicates there was no Ops/s in any protocol (SMB, FTP, HTTP, ISCSI, NFS, and HDFS).

How can we understand the different outputs?

Thank you,