title: Max value along with timestamp retrieval in opentsdb
body: <p>Say, I have below time series for metric <code>cpu.load_1min</code></p>
  
  <pre>
  t0    t1    t2    t3    t4    t5    t6    t7    t8    t9
   0    10    90    20    80    30    70    40    60    50
  </pre>
  
  <p>I wanna extract the highest value along with its timestamp. in above case it's <code>&lt;t2, 90&gt;</code>. I also want the timestamp to be the exact timestamp without downsampling.</p>
  
  <p>And I'm talking about generating a 3-month timespan report for over 10 thousand servers. So querying them all back and then do the max operation myself is really not my option.</p>
  
  <p>I found that <code>/api/query</code> or <code>/api/query/exp</code> could not do it</p>
  
  <p>Please help me out, thx.</p>