Unknown error for documents

I have a 6 node cluster with 2 replicas (this also happens on a 3 node cluster with 1 replica) running couchbase community 4.5

When I take 1 node in the 6 node cluster down, then navigate in the UI to Data Buckets, then click on Documents for my default bucket, the UI shows:

Error: unknown error ({exit, {{nodedown,‘ns_1@(server name)’}, {gen_server,call, [{‘ns_memcached-default’,‘ns_1@pchdccouch01d.amers3.cis.trcloud’}, {get_keys, [137,138,139,140,141,142,143,144,145,146,147,148,149,150,151, 152,153,154,155,156,157,158,159,160,161,162,163,164,165,166, 167,168,169,170,308,309,310,311,312,313,314,315,316,317,318, 319,320,321,322,323,324,325,326,327,328,329,330,331,332,333, 334,335,336,337,338,339,340,341,342,343,344,345,346,347,348, 349,350,351,352,353,354,355,356,357,358,359,360,361,362,363, 364,365,366,367,368,369,370,371,372,373,374,375,376,479,480, 481,482,483,484,485,486,487,488,489,490,491,492,493,494,495, 496,497,498,499,500,501,502,503,504,505,506,507,508,509,510, 511,512,683,684,685,686,687,688,689,690,691,692,693,694,695, 696,697,698,699,700,701,702,703,704,705,706,707,708,709,710, 711,712,713,714,715,716], [{include_docs,true}, {inclusive_end,true}, {limit,6}, {start_key,undefined}, {end_key,undefined}]}, infinity]}}})

When i restart the node that I took down I can then see the documents again. Any reason for this?

I am also facing same error .Can anyone help pls!

Can you define what you mean by “take 1 node in the 6 node cluster down”? Are you talking about:

  1. Doing a remove node/rebalance?
  2. Doing a graceful failover?
  3. Doing a hard failover?
  4. Just shutting the node down and leaving it down?

It seems like this is probably a defect in the UI, but a relatively harmless one. You might be able to use the query UI as a workaround (assuming you have the query service configured and a primary index) or the cbc cat utility included with libcouchbase to access documents on the not-down nodes.