Slow response times from Azure table storage

I am using Azure Table Storage from my PHP application and I am seeing very slow response times. The application collects reports every day for each user and puts them in a section using the section key $userID . date("dmY")

. During load testing on one particular day, several thousand reports were generated that require multiple trips to retrieve because of the 1000 entities in an Azure table storage query. Each trip to retrieve 1000 objects can take up to 2 seconds.

Code:

for($i = 0; $i < $daysToGoBack; $i++)
{
    $filter = "PartitionKey eq '" . $userId . date("dmY", strtotime("-$i days")) . "'";

    $options = new QueryEntitiesOptions();
    $options->addSelectField('created');
    $options->setFilter(Filter::applyQueryString($filter));

    $this->benchmark->mark('main_query');

    $result = $this->tableRestProxy->queryEntities('reports', $filter, $options);

    $this->benchmark->mark('main_query_end');
    echo "Query: " . $this->benchmark->elapsed_time('main_query', 'main_query_end') . "<br/>";

    $entities = array_merge($result->getEntities(), $entities);

    $nextPartitionKey = $result->getNextPartitionKey();
    $nextRowKey = $result->getNextRowKey();

    while(!is_null($nextRowKey) && !is_null($nextPartitionKey)) 
    {
        $options = new QueryEntitiesOptions();
        $options->setNextPartitionKey($nextPartitionKey);
        $options->setNextRowKey($nextRowKey);
        $options->addSelectField('created');
        $options->setFilter(Filter::applyQueryString($filter));

        $this->benchmark->mark('sub_query');

        $newResult = $this->tableRestProxy->queryEntities('reports', $options);

        $this->benchmark->mark('sub_query_end');
        echo "Continuation: " . $this->benchmark->elapsed_time('sub_query', 'sub_query_end') . "<br/>";

        $newEntities = $newResult->getEntities();

        $entities = array_merge($newEntities, $entities);

        $nextPartitionKey = $newResult->getNextPartitionKey();
        $nextRowKey = $newResult->getNextRowKey();
    }

      

        
        
        
      

    

Result:

Query: 1.8183
Continuation: 1.2479
Continuation: 0.2423
Continuation: 0.2619
Continuation: 0.2476
Continuation: 0.2836
Continuation: 0.2345
Continuation: 0.2482
Continuation: 0.2565
Continuation: 0.2187
Continuation: 0.2319
Continuation: 0.2389
Continuation: 0.2221
Query: 0.0320
Query: 0.0338
Query: 0.1038
Query: 0.1263
Query: 0.1841
Query: 0.0547

      

        
        
        
      

    

The above results are the best I could get from this. The first request has nearly 13,000 reports to back off the same as the original request, followed by 12 callbacks with a continuation token. In most cases, queries can take much longer on exactly the same data.

Query: 1.8273
Continuation: 1.2592
Continuation: 0.8160
Continuation: 0.8463
Continuation: 0.7474
Continuation: 0.7104
Continuation: 1.3987
Continuation: 1.4321
Continuation: 1.4526
Continuation: 1.3184
Continuation: 0.7390
Continuation: 0.7212
Continuation: 0.2610
Query: 0.0630
Query: 0.1221
Query: 0.0728
Query: 0.1250
Query: 0.1717
Query: 0.0568

      

        
        
        
      

    

Are these results expected from Azure, or is there a better way to query this data?