Getting timeout execptions and indexfailure execptions

I am getting below errors during load testing. Any idea why I may be getting these errors

error: The server reported an issue with the underlying index, com.couchbase.client.core.error.IndexFailureException: The server reported an issue with the underlying index {“completed”:true,“coreId”:“0x3ec6c7400000001”,“errors”:[{“additional”:{“retry”:true},“code”:12008,“message”:“Error performing bulk get operation - cause: {1 errors, starting with bulkget exceeded MaxBulkRetries for TESTBUCKET(vbid:567,keys:[Index1498AE06B6410488CB86F80914F08119B1630036800000])}”}]

com.couchbase.client.core.error.AmbiguousTimeoutException: QueryRequest, Reason: TIMEOUT {“cancelled”:true,“completed”:true,“coreId”:“0x3ec6c7400000001”,“idempotent”:false,“lastDispatchedFrom”:“xx.xxx.x.xx:55518”,“lastDispatchedTo”:“xxxx.xx.xxx.xx:8093”,“reason”:“TIMEOUT”,“requestId”:485019,“requestType”:“QueryRequest”,“retried”:12,“retryReasons”:[“ENDPOINT_NOT_AVAILABLE”]