SQL Server Input Plugin - Some counters are missing with CS or BIN server collations

[mikedavem]

Relevant telegraf.conf:

[[inputs.sqlserver]]

  servers = [
     "Server=xxxx;Port=xxxx;User Id=telegraf;Password=xxxx;app name=telegraf;log=1;"
  ]

  query_version = 2

  ## If you would like to exclude some of the metrics queries, list them here
  ## Possible choices:
  ## - PerformanceCounters
  ## - WaitStatsCategorized
  ## - DatabaseIO
  ## - DatabaseProperties
  ## - CPUHistory
  ## - DatabaseSize
  ## - DatabaseStats
  ## - MemoryClerk
  ## - VolumeSpace
  ## - Schedulers
  ## - AzureDBResourceStats
  ## - AzureDBResourceGovernance
  ## - SqlRequests
  ## - ServerProperties
  ## exclude_query = ['PerformanceCounters']

System info:

Microsoft Windows Server 2016 Datacenter

Steps to reproduce:

1. With SQL Server collation Latin1_General_100_BIN2

Expected behavior:

All counters defined in PerformanceCounters metric queries should be collected

Actual behavior:

Some counters PerformanceCounters metric queries are not collected due to their wrong case if we are using CS or BIN based server collation including:

'Page Lookups/sec' --> 'Page lookups/sec'
'Page Reads/sec' --> 'Page reads/sec',
'Page Writes/sec' --> 'Page writes/sec',
'Readahead Pages/sec' --> 'Readahead pages/sec'
'Lazy Writes/sec' --> Lazy writes/sec
'Checkpoint Pages/sec' --> Checkpoint pages/sec
'Group Commits/sec' --> Group Commits/Sec

Additional info: