ElasticSearch debugging from red to green

We are looking for a tech to do ElasticSearch debugging. Our cluster health: red (1, 6). We want tech to do maintenance, debug and fix and bring it back to green. Cluster Statistics 1 Nodes 14 Total Shards 6 Successful Shards 3 Indices 23,389,116 Documents 5.8GB Size Index # Docs Primary Size # Shards # Replicas Status index1 19,733,091 3.4GB 1 1 open index2 56,348 292.1MB 5 1 open index3 3,599,677 2.1GB 1 1 open Status Red Timed Out? false # Nodes 1 # Data Nodes 1 Active Primary Shards 6 Active Shards 6 Relocating Shards 0 Initializing Shards 0 Unassigned Shards 8 Our Stats: File System Store Size: 5.8GB # Documents: 23,389,116 Documents Deleted: 5.7% Merge Size: 0.0 Merge Time: 00:00:00 Merge Rate: 0 MB/s File Descriptors: 800 Index Activity Indexing - Index: 0.15ms Indexing - Delete: 0ms Search - Query: 0.43ms Search - Fetch: 0.38ms Get - Total: 0.02ms Get - Exists: 0.02ms Get - Missing: 0.02ms Refresh: 19.61ms Flush: 57.74ms Cache Activity Field Size: 116.3MB Field Evictions: 0 Filter Cache Size: 8.8MB Filter Evictions: 0 per query ID Cache Size: 0b % ID Cache: 0% Memory Total Memory: 63 gb Heap Size: 0.8 gb Heap % of RAM: 1.3% % Heap Used: 50.8% GC MarkSweep Frequency: 5,163 s GC MarkSweep Duration: 10.41ms GC ParNew Frequency: 25 s GC ParNew Duration: 2.21ms G1 GC Young Generation Freq: 0 s G1 GC Young Generation Duration: 0ms G1 GC Old Generation Freq: 0 s G1 GC Old Generation Duration: 0ms Swap Space: 0.5781 mb Network HTTP Connection Rate: 42 /second