[SOLR-10677] Expose a diagnostics API to return nodes sorted by load in descending order and any policy violations

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 7.0
• Component/s: SolrCloud
• Labels: autoscaling
• Assignee: Shalin Shekhar Mangar
• Reporter: Shalin Shekhar Mangar
• Created: 12/May/17 08:07
• Updated: 13/Jun/17 06:31
• Resolved: 29/May/17 16:17

Description

Expose a diagnostics API to gives details of how loaded each node is, according to the configured cluster policy and preferences as well as a list of violations for rules given in the policies.

By adding /diagnostics to the /admin/autoscaling path (for v1 API) or /cluster/autoscaling path (for v2 API), the API returns the list of nodes in sorted order according to the cluster preferences configured.

API v1:

curl http://localhost:8983/solr/admin/autoscaling/diagnostics

or API v2:

http://localhost:8983/v2/cluster/autoscaling/diagnostics

{
  "responseHeader":{
    "status":0,
    "QTime":30},
  "cluster-policy":[{
      "cores":"<10",
      "node":"#ANY"},
    {
      "replica":"<2",
      "shard":"#EACH",
      "node":"#ANY"},
    {
      "nodeRole":"!overseer",
      "replica":"#ANY"}],
  "cluster-preferences":[{
      "minimize":"cores",
      "precision":3},
    {
      "maximize":"freedisk",
      "precision":100},
    {
      "minimize":"sysLoadAvg",
      "precision":10},
    {
      "minimize":"heapUsage",
      "precision":10}],
  "diagnostics":{
    "sortedNodes":[{
        "node":"127.0.1.1:8983_solr",
        "cores":2,
        "freedisk":69.68052673339844,
        "sysLoadAvg":77.0,
        "heapUsage":17.253869804602918},
      {
        "node":"127.0.1.1:7574_solr",
        "cores":2,
        "freedisk":69.68052673339844,
        "sysLoadAvg":77.0,
        "heapUsage":6.980811063081137}],
    "violations":[]},
  "WARNING":"This response format is experimental.  It is likely to change in the future."}