c# 超过 100 个结果在循环中超时

Question

I have a controller that returns a list of records from a database. If I request 100 results it returns within 6-8 seconds. If I request 500 results it times out .

I have debugged the code and found that the EF Core database query is not the issue, it only takes 10-20ms.

There are nearly identical controllers/extensions to this and they all return < 1 sec. Not sure what is happening here.

Here is the associated code:

Controller Endpoint

[HttpGet("Summary")]
[AutoQuery]
[ProducesResponseType(200, Type = typeof(CollectionDTO<MemberCardQueueEntrySummary>))]
public async Task<IActionResult> GetSummary()
{
    // NOTE: takes 10-20ms
    var entries = await memberService.MemberCardQueueEntries().Include(x => x.Account).ThenInclude(x => x.Division).ApplyAutoQuery(HttpContext.Request.Query.ParseQueryString(), out int total).ToListAsync();

    // NOTE: takes 6-8 seconds for smaller result sets and times outs for larger
    var summaries = entries.ToMemberCardQueueEntrySummaryAsync(mapper);
    var results = summaries.ToList();
    return Ok(new CollectionDTO<MemberCardQueueEntrySummary>
    {
        Count = results.Count,
        Total = total,
        Data = results
    });
}

Extension method that converts one model to the next

public static class MemberCardQueueEntryExtensions
{
    public static IEnumerable<MemberCardQueueEntrySummary> ToMemberCardQueueEntrySummaryAsync(this IEnumerable<MemberCardQueueEntry> entries, IMapper mapper)
    {
        var result = new List<MemberCardQueueEntrySummary>();
        foreach (var x in entries)
        {
            result.Add(x.ToMemberCardQueueEntrySummaryAsync(mapper));
        }
        return result;
    }

    public static MemberCardQueueEntrySummary ToMemberCardQueueEntrySummaryAsync(this MemberCardQueueEntry entry, IMapper mapper)
    {
        var result = mapper.Map<MemberCardQueueEntrySummary>(entry);
        result.AccountName = entry?.Account?.Name;
        result.DivisionName = entry?.Account?.Division?.Name;
        return result;
    }
}

Auto mapper config

cfg.CreateMap<MemberCardQueueEntry, MemberCardQueueEntry>()
    .IgnoreAllVirtual();
cfg.CreateMap<MemberCardQueueEntry, MemberCardQueueEntryDTO>()
    .IgnoreAllVirtual()
    .ReverseMap();
cfg.CreateMap<MemberCardQueueEntry, MemberCardQueueEntrySummary>()
    .IgnoreAllVirtual();

Answer 1

Have you tried using manual mapper instead of using auto mapper? so you don't have to carry every parameter in the automapper.

At least you can see if there is a problem with the mapper or your objects.

Example :
public MemberCardQueueEntrySummary MapTo(MemberCardQueueEntry entry){
    AccountName = entry?.Account?.Name;
    DivisionName = entry?.Account?.Division?.Name;
    ......

}

Answer 2

Find out time of request without autoMapper. Auto mapper works longer where value get null.