Add NFS Server metrics collector. (#803)

* Add NFS Server metrics collector.

* Add File Handles metrics.

* Add nfsd IO stats.

* Add metrics for NFSd threads.

* Add metrics for NFSd read ahead cache.

* Add NFSd network traffic counters.

* Add RPC metrics.

* Add V2 requests metrics.

* Add NFSv3 metrics.

* Add NFSv4 metrics.

* Update reply cache comment.

* Update help text.

collector/fixtures/e2e-output.txt

@@ -2576,6 +2576,121 @@ node_nfs_rpc_operations 1.218785755e+09
 # HELP node_nfs_rpc_retransmissions Number of RPC transmissions performed.
 # TYPE node_nfs_rpc_retransmissions counter
 node_nfs_rpc_retransmissions 374636
+# HELP node_nfsd_connections_total Total number of NFSd TCP connections.
+# TYPE node_nfsd_connections_total counter
+node_nfsd_connections_total 1
+# HELP node_nfsd_disk_bytes_read_total Total NFSd bytes read.
+# TYPE node_nfsd_disk_bytes_read_total counter
+node_nfsd_disk_bytes_read_total 1.572864e+08
+# HELP node_nfsd_disk_bytes_written_total Total NFSd bytes written.
+# TYPE node_nfsd_disk_bytes_written_total counter
+node_nfsd_disk_bytes_written_total 72864
+# HELP node_nfsd_file_handles_stale_total Total number of NFSd stale file handles
+# TYPE node_nfsd_file_handles_stale_total counter
+node_nfsd_file_handles_stale_total 0
+# HELP node_nfsd_packets_total Total NFSd network packets (sent+recieved) by protocol type.
+# TYPE node_nfsd_packets_total counter
+node_nfsd_packets_total{proto="tcp"} 917
+node_nfsd_packets_total{proto="udp"} 55
+# HELP node_nfsd_read_ahead_cache_not_found_total Total number of NFSd read ahead cache not found.
+# TYPE node_nfsd_read_ahead_cache_not_found_total counter
+node_nfsd_read_ahead_cache_not_found_total 0
+# HELP node_nfsd_read_ahead_cache_size_blocks How large the read ahead cache is in blocks.
+# TYPE node_nfsd_read_ahead_cache_size_blocks gauge
+node_nfsd_read_ahead_cache_size_blocks 32
+# HELP node_nfsd_reply_cache_hits_total Total number of NFSd Reply Cache hits (client lost server response).
+# TYPE node_nfsd_reply_cache_hits_total counter
+node_nfsd_reply_cache_hits_total 0
+# HELP node_nfsd_reply_cache_misses_total Total number of NFSd Reply Cache an operation that requires caching (idempotent).
+# TYPE node_nfsd_reply_cache_misses_total counter
+node_nfsd_reply_cache_misses_total 6
+# HELP node_nfsd_reply_cache_nocache_total Total number of NFSd Reply Cache non-idempotent operations (rename/delete/…).
+# TYPE node_nfsd_reply_cache_nocache_total counter
+node_nfsd_reply_cache_nocache_total 18622
+# HELP node_nfsd_requests_total Total number NFSd Requests by method and protocol.
+# TYPE node_nfsd_requests_total counter
+node_nfsd_requests_total{method="Access",proto="v3"} 111
+node_nfsd_requests_total{method="Access",proto="v4"} 1098
+node_nfsd_requests_total{method="Close",proto="v4"} 2
+node_nfsd_requests_total{method="Commit",proto="v3"} 0
+node_nfsd_requests_total{method="Commit",proto="v4"} 0
+node_nfsd_requests_total{method="Create",proto="v2"} 0
+node_nfsd_requests_total{method="Create",proto="v3"} 0
+node_nfsd_requests_total{method="Create",proto="v4"} 0
+node_nfsd_requests_total{method="DelegPurge",proto="v4"} 0
+node_nfsd_requests_total{method="DelegReturn",proto="v4"} 0
+node_nfsd_requests_total{method="FsInfo",proto="v3"} 2
+node_nfsd_requests_total{method="FsStat",proto="v2"} 2
+node_nfsd_requests_total{method="FsStat",proto="v3"} 0
+node_nfsd_requests_total{method="GetAttr",proto="v2"} 69
+node_nfsd_requests_total{method="GetAttr",proto="v3"} 112
+node_nfsd_requests_total{method="GetAttr",proto="v4"} 8179
+node_nfsd_requests_total{method="GetFH",proto="v4"} 5896
+node_nfsd_requests_total{method="Link",proto="v2"} 0
+node_nfsd_requests_total{method="Link",proto="v3"} 0
+node_nfsd_requests_total{method="Link",proto="v4"} 0
+node_nfsd_requests_total{method="Lock",proto="v4"} 0
+node_nfsd_requests_total{method="Lockt",proto="v4"} 0
+node_nfsd_requests_total{method="Locku",proto="v4"} 0
+node_nfsd_requests_total{method="Lookup",proto="v2"} 4410
+node_nfsd_requests_total{method="Lookup",proto="v3"} 2719
+node_nfsd_requests_total{method="Lookup",proto="v4"} 5900
+node_nfsd_requests_total{method="LookupRoot",proto="v4"} 0
+node_nfsd_requests_total{method="MkDir",proto="v2"} 0
+node_nfsd_requests_total{method="MkDir",proto="v3"} 0
+node_nfsd_requests_total{method="MkNod",proto="v3"} 0
+node_nfsd_requests_total{method="Nverify",proto="v4"} 0
+node_nfsd_requests_total{method="Open",proto="v4"} 2
+node_nfsd_requests_total{method="OpenAttr",proto="v4"} 0
+node_nfsd_requests_total{method="OpenConfirm",proto="v4"} 2
+node_nfsd_requests_total{method="OpenDgrd",proto="v4"} 0
+node_nfsd_requests_total{method="PathConf",proto="v3"} 1
+node_nfsd_requests_total{method="PutFH",proto="v4"} 9609
+node_nfsd_requests_total{method="Read",proto="v2"} 0
+node_nfsd_requests_total{method="Read",proto="v3"} 0
+node_nfsd_requests_total{method="Read",proto="v4"} 150
+node_nfsd_requests_total{method="ReadDir",proto="v2"} 99
+node_nfsd_requests_total{method="ReadDir",proto="v3"} 27
+node_nfsd_requests_total{method="ReadDir",proto="v4"} 1272
+node_nfsd_requests_total{method="ReadDirPlus",proto="v3"} 216
+node_nfsd_requests_total{method="ReadLink",proto="v2"} 0
+node_nfsd_requests_total{method="ReadLink",proto="v3"} 0
+node_nfsd_requests_total{method="ReadLink",proto="v4"} 0
+node_nfsd_requests_total{method="RelLockOwner",proto="v4"} 0
+node_nfsd_requests_total{method="Remove",proto="v2"} 0
+node_nfsd_requests_total{method="Remove",proto="v3"} 0
+node_nfsd_requests_total{method="Remove",proto="v4"} 0
+node_nfsd_requests_total{method="Rename",proto="v2"} 0
+node_nfsd_requests_total{method="Rename",proto="v3"} 0
+node_nfsd_requests_total{method="Rename",proto="v4"} 0
+node_nfsd_requests_total{method="Renew",proto="v4"} 1236
+node_nfsd_requests_total{method="RestoreFH",proto="v4"} 0
+node_nfsd_requests_total{method="RmDir",proto="v2"} 0
+node_nfsd_requests_total{method="RmDir",proto="v3"} 0
+node_nfsd_requests_total{method="Root",proto="v2"} 0
+node_nfsd_requests_total{method="SaveFH",proto="v4"} 0
+node_nfsd_requests_total{method="SecInfo",proto="v4"} 0
+node_nfsd_requests_total{method="SetAttr",proto="v2"} 0
+node_nfsd_requests_total{method="SetAttr",proto="v3"} 0
+node_nfsd_requests_total{method="SetAttr",proto="v4"} 0
+node_nfsd_requests_total{method="SymLink",proto="v2"} 0
+node_nfsd_requests_total{method="SymLink",proto="v3"} 0
+node_nfsd_requests_total{method="Verify",proto="v4"} 3
+node_nfsd_requests_total{method="WrCache",proto="v2"} 0
+node_nfsd_requests_total{method="Write",proto="v2"} 0
+node_nfsd_requests_total{method="Write",proto="v3"} 0
+node_nfsd_requests_total{method="Write",proto="v4"} 3
+# HELP node_nfsd_rpc_errors_total Total number of NFSd RPC errors by error type.
+# TYPE node_nfsd_rpc_errors_total counter
+node_nfsd_rpc_errors_total{error="auth"} 2
+node_nfsd_rpc_errors_total{error="cInt"} 0
+node_nfsd_rpc_errors_total{error="fmt"} 1
+# HELP node_nfsd_server_rpcs_total Total number of NFSd RPCs.
+# TYPE node_nfsd_server_rpcs_total gauge
+node_nfsd_server_rpcs_total 18628
+# HELP node_nfsd_server_threads Total number of NFSd kernel threads that are running.
+# TYPE node_nfsd_server_threads gauge
+node_nfsd_server_threads 8
 # HELP node_procs_blocked Number of processes blocked waiting for I/O to complete.
 # TYPE node_procs_blocked gauge
 node_procs_blocked 0
@@ -2630,6 +2745,7 @@ node_scrape_collector_success{collector="mountstats"} 1
 node_scrape_collector_success{collector="netdev"} 1
 node_scrape_collector_success{collector="netstat"} 1
 node_scrape_collector_success{collector="nfs"} 1
+node_scrape_collector_success{collector="nfsd"} 1
 node_scrape_collector_success{collector="qdisc"} 1
 node_scrape_collector_success{collector="sockstat"} 1
 node_scrape_collector_success{collector="stat"} 1

collector/fixtures/proc/net/rpc/nfsd

@@ -0,0 +1,11 @@
+rc 0 6 18622
+fh 0 0 0 0 0
+io 157286400 72864
+th 8 0 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
+ra 32 0 0 0 0 0 0 0 0 0 0 0
+net 972 55 917 1
+rpc 18628 3 1 2 0
+proc2 18 2 69 0 0 4410 0 0 0 0 0 0 0 0 0 0 0 99 2
+proc3 22 2 112 0 2719 111 0 0 0 0 0 0 0 0 0 0 0 27 216 0 2 1 0
+proc4 2 2 10853
+proc4ops 72 0 0 0 1098 2 0 0 0 0 8179 5896 0 0 0 0 5900 0 0 2 0 2 0 9609 0 2 150 1272 0 0 0 1236 0 0 0 0 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0