Add file descriptor details to cat/nodes

cat/nodes currently does not report any details related to file descriptors. This adds the current number in use, the maximum number available as well as their ratio (percentage) to cat/nodes as hidden-by-default metrics. In addition, this also adds current heap usage (as a non-percentage of ts max) and ram usage (as a non-percerntage of its max) to allow tools to provide more granularity.

Closes #7652

docs/reference/cat/nodes.asciidoc

@@ -90,10 +90,18 @@ k0zy 192.168.56.10 9300 {version} m
 |`build` |`b` |No |Elasticsearch Build hash |5c03844
 |`jdk` |`j` |No |Running Java version |1.8.0
 |`disk.avail` |`d`, `disk`, `diskAvail` |No |Available disk space |1.8gb
-|`heap.percent` |`hp`, `heapPercent` |No |Used heap percentage |7
+|`heap.current` |`hc`, `heapCurrent` |No |Used heap |311.2mb
+|`heap.percent` |`hp`, `heapPercent` |Yes |Used heap percentage |7
 |`heap.max` |`hm`, `heapMax` |No |Maximum configured heap |1015.6mb
-|`ram.percent` |`rp`, `ramPercent` |No |Used total memory percentage |47
+|`ram.current` |`rc`, `ramCurrent` |No |Used total memory |513.4mb
+|`ram.percent` |`rp`, `ramPercent` |Yes |Used total memory percentage |47
 |`ram.max` |`rm`, `ramMax` |No |Total memory |2.9gb
+|`file_desc.current` |`fdc`, `fileDescriptorCurrent` |No |Used file
+descriptors |123
+|`file_desc.percent` |`fdp`, `fileDescriptorPercent` |Yes |Used file
+descriptors percentage |1
+|`file_desc.max` |`fdm`, `fileDescriptorMax` |No |Maximum number of file
+descriptors |1024
 |`load` |`l` |No |Most recent load average |0.22
 |`uptime` |`u` |No |Node uptime |17.3m
 |`node.role` |`r`, `role`, `dc`, `nodeRole` |Yes |Data node (d); Client

rest-api-spec/test/cat.nodes/10_basic.yaml

@@ -0,0 +1,39 @@
+---
+"Test cat nodes output":
+
+  - do:
+      cat.nodes: {}
+
+  - match:
+      $body: |
+               /  #host       ip                          heap.percent        ram.percent      load        node.role        master         name
+               ^  (\S+   \s+  (\d{1,3}\.){3}\d{1,3}  \s+  \d+            \s+  \d*         \s+  \d*    \s+  [-dc]       \s+  [-*mx]    \s+   \S+   \s+  \n)+  $/
+
+  - do:
+      cat.nodes:
+          v: true
+
+  - match:
+      $body: |
+               /^  host  \s+  ip                     \s+  heap\.percent   \s+  ram\.percent \s+  load   \s+  node\.role   \s+  master   \s+   name   \s+  \n
+                  (\S+   \s+  (\d{1,3}\.){3}\d{1,3}  \s+  \d+             \s+  \d*          \s+  \d*    \s+  [-dc]        \s+  [-*mx]    \s+   \S+   \s+  \n)+  $/
+
+  - do:
+      cat.nodes:
+          h: heap.current,heap.percent,heap.max
+          v: true
+
+  - match:
+      $body: |
+               /^      heap\.current          \s+  heap\.percent  \s+  heap\.max             \s+ \n
+                  (\s+ \d+(\.\d+)?[ptgmk]?b   \s+  \d+            \s+  \d+(\.\d+)?[ptgmk]?b  \s+ \n)+  $/
+
+  - do:
+      cat.nodes:
+          h: file_desc.current,file_desc.percent,file_desc.max
+          v: true
+
+  - match:
+      $body: |
+               /^      file_desc\.current  \s+  file_desc\.percent  \s+  file_desc\.max  \s+ \n
+                  (\s+ \d+                 \s+  \d+                 \s+  \d+             \s+ \n)+  $/

src/main/java/org/elasticsearch/rest/action/cat/RestNodesAction.java

@@ -73,7 +73,7 @@ public class RestNodesAction extends AbstractCatAction {
                     @Override
                     public void processResponse(final NodesInfoResponse nodesInfoResponse) {
                         NodesStatsRequest nodesStatsRequest = new NodesStatsRequest();
-                        nodesStatsRequest.clear().jvm(true).os(true).fs(true).indices(true);
+                        nodesStatsRequest.clear().jvm(true).os(true).fs(true).indices(true).process(true);
                         client.admin().cluster().nodesStats(nodesStatsRequest, new RestResponseListener<NodesStatsResponse>(channel) {
                             @Override
                             public RestResponse buildResponse(NodesStatsResponse nodesStatsResponse) throws Exception {
@@ -100,10 +100,15 @@ public class RestNodesAction extends AbstractCatAction {
         table.addCell("build", "default:false;alias:b;desc:es build hash");
         table.addCell("jdk", "default:false;alias:j;desc:jdk version");
         table.addCell("disk.avail", "default:false;alias:d,disk,diskAvail;text-align:right;desc:available disk space");
+        table.addCell("heap.current", "default:false;alias:hc,heapCurrent;text-align:right;desc:used heap");
         table.addCell("heap.percent", "alias:hp,heapPercent;text-align:right;desc:used heap ratio");
         table.addCell("heap.max", "default:false;alias:hm,heapMax;text-align:right;desc:max configured heap");
+        table.addCell("ram.current", "default:false;alias:rc,ramCurrent;text-align:right;desc:used machine memory");
         table.addCell("ram.percent", "alias:rp,ramPercent;text-align:right;desc:used machine memory ratio");
         table.addCell("ram.max", "default:false;alias:rm,ramMax;text-align:right;desc:total machine memory");
+        table.addCell("file_desc.current", "default:false;alias:fdc,fileDescriptorCurrent;text-align:right;desc:used file descriptors");
+        table.addCell("file_desc.percent", "default:false;alias:fdp,fileDescriptorPercent;text-align:right;desc:used file descriptor ratio");
+        table.addCell("file_desc.max", "default:false;alias:fdm,fileDescriptorMax;text-align:right;desc:max file descriptors");
 
         table.addCell("load", "alias:l;text-align:right;desc:most recent load avg");
         table.addCell("uptime", "default:false;alias:u;text-align:right;desc:node uptime");
@@ -211,10 +216,16 @@ public class RestNodesAction extends AbstractCatAction {
             table.addCell(info == null ? null : info.getBuild().hashShort());
             table.addCell(info == null ? null : info.getJvm().version());
             table.addCell(stats == null ? null : stats.getFs() == null ? null : stats.getFs().total().getAvailable());
+            table.addCell(stats == null ? null : stats.getJvm().getMem().getHeapUsed());
             table.addCell(stats == null ? null : stats.getJvm().getMem().getHeapUsedPrecent());
             table.addCell(info == null ? null : info.getJvm().getMem().getHeapMax());
+            table.addCell(stats == null ? null : stats.getOs().mem() == null ? null : stats.getOs().mem().used());
             table.addCell(stats == null ? null : stats.getOs().mem() == null ? null : stats.getOs().mem().usedPercent());
             table.addCell(info == null ? null : info.getOs().mem() == null ? null : info.getOs().mem().total()); // sigar fails to load in IntelliJ
+            table.addCell(stats == null ? null : stats.getProcess().getOpenFileDescriptors());
+            table.addCell(stats == null || info == null ? null :
+                          calculatePercentage(stats.getProcess().getOpenFileDescriptors(), info.getProcess().getMaxFileDescriptors()));
+            table.addCell(info == null ? null : info.getProcess().getMaxFileDescriptors());
 
             table.addCell(stats == null ? null : stats.getOs() == null ? null : stats.getOs().getLoadAverage().length < 1 ? null : String.format(Locale.ROOT, "%.2f", stats.getOs().getLoadAverage()[0]));
             table.addCell(stats == null ? null : stats.getJvm().uptime());
@@ -296,4 +307,14 @@ public class RestNodesAction extends AbstractCatAction {
 
         return table;
     }
+
+    /**
+     * Calculate the percentage of {@code used} from the {@code max} number.
+     * @param used The currently used number.
+     * @param max The maximum number.
+     * @return 0 if {@code max} is 0. Otherwise 100 * {@code used} / {@code max}.
+     */
+    private short calculatePercentage(long used, long max) {
+        return max == 0 ? 0 : (short)((100d * used) / max);
+    }
 }