Re: [PATCH] nfsiostat/mountstats: handle KeyError in compare_iostats()

[Steve Dickson <SteveD@RedHat.com>]

On 7/8/20 12:06 PM, Kenneth D'souza wrote:
> This will prevent a backtrace like this from occurring if nfsiostat is run
> with <interval> <count>, eg: nfsiostat 1 3
> This issue can occur if old_stats.__rpc_data['ops'] keys are not up to
> date with result.__rpc_data['ops'].
> I belive this issue can also affect mountstats due to similar code,
> hence fix it too.
> 
> nfsiostat:217:compare_iostats:KeyError: 'NULL'
> 
> Traceback (most recent call last):
>   File "/usr/sbin/nfsiostat", line 649, in <module>
>     iostat_command(prog)
>   File "/usr/sbin/nfsiostat", line 617, in iostat_command
>     print_iostat_summary(old_mountstats, mountstats, devices, sample_time, options)
>   File "/usr/sbin/nfsiostat", line 468, in print_iostat_summary
>     diff_stats[device] = stats[device].compare_iostats(old_stats)
>   File "/usr/sbin/nfsiostat", line 217, in compare_iostats
>     difference, self.__rpc_data[op], old_stats.__rpc_data[op]))
> KeyError: 'NULL'
> 
> Signed-off-by: Kenneth D'souza <kdsouza@redhat.com>
Committed... (tag: nfs-utils-2-5-2-rc2

steved.
> ---
>  tools/mountstats/mountstats.py | 5 ++++-
>  tools/nfs-iostat/nfs-iostat.py | 7 +++++--
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/mountstats/mountstats.py b/tools/mountstats/mountstats.py
> index 014f38a3..1054f698 100755
> --- a/tools/mountstats/mountstats.py
> +++ b/tools/mountstats/mountstats.py
> @@ -560,7 +560,10 @@ class DeviceData:
>          # the reference to them.  so we build new lists here
>          # for the result object.
>          for op in result.__rpc_data['ops']:
> -            result.__rpc_data[op] = list(map(difference, self.__rpc_data[op], old_stats.__rpc_data[op]))
> +            try:
> +                result.__rpc_data[op] = list(map(difference, self.__rpc_data[op], old_stats.__rpc_data[op]))
> +            except KeyError:
> +                continue
>  
>          # update the remaining keys
>          if protocol == 'udp':
> diff --git a/tools/nfs-iostat/nfs-iostat.py b/tools/nfs-iostat/nfs-iostat.py
> index b7e98a2a..5556f692 100755
> --- a/tools/nfs-iostat/nfs-iostat.py
> +++ b/tools/nfs-iostat/nfs-iostat.py
> @@ -213,8 +213,11 @@ class DeviceData:
>          # the reference to them.  so we build new lists here
>          # for the result object.
>          for op in result.__rpc_data['ops']:
> -            result.__rpc_data[op] = list(map(
> -                difference, self.__rpc_data[op], old_stats.__rpc_data[op]))
> +            try:
> +                result.__rpc_data[op] = list(map(
> +                    difference, self.__rpc_data[op], old_stats.__rpc_data[op]))
> +            except KeyError:
> +                continue
>  
>          # update the remaining keys we care about
>          result.__rpc_data['rpcsends'] -= old_stats.__rpc_data['rpcsends']
>