MySQL5.6升级5.7时出现主从延迟问题排查过程

=============5.6===============================
---BUFFER POOL 1
Buffer pool size 655359
Buffer pool size, bytes 10737401856
Free buffers 1019
Database pages 649599
Old database pages 239773
Modified db pages 119309
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 10777670, not young 181119246
13.90 youngs/s, 157.51 non-youngs/s
Pages read 8853516, created 135760152, written 784514803
20.96 reads/s, 58.17 creates/s, 507.02 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 2 / 1000
Pages read ahead 0.00/s, evicted without aess 0.00/s, Random read ahead 0.00/s
LRU len: 649599, unzip_LRU len: 0
I/O sum[209618]:cur[2], unzip sum[0]:cur[0]

=============5.7==============================
---BUFFER POOL 1
Buffer pool size 819100
Buffer pool size, bytes 13420134400
Free buffers 1018
Database pages 722328
Old database pages 266620
Modified db pages 99073
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 37153, not young 795
0.00 youngs/s, 0.00 non-youngs/s
Pages read 149632, created 572696, written 2706369
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without aess 0.00/s, Random read ahead 0.00/s
LRU len: 722328, unzip_LRU len: 453903
I/O sum[98685]:cur[0], unzip sum[882]:cur[6]
+++++++++++++++++++++++

CREATE TABLE trends (
itemid bigint(20) unsigned NOT NULL,
clock int(11) NOT NULL DEFAULT '0',
num int(11) NOT NULL DEFAULT '0',
value_min double(16,4) NOT NULL DEFAULT '0.0000',
value_avg double(16,4) NOT NULL DEFAULT '0.0000',
value_max double(16,4) NOT NULL DEFAULT '0.0000',
PRIMARY KEY (itemid,clock),
KEY clock (clock)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=8