kafka 发送消息 BLOCKED 问题

生产项目上kafka单体消息比较大，而且消息发送频率也比较高，近期cpu总是飙升，影响服务正常使用，使用jstack导出线程信息，发现如下有用信息：

 java.lang.Thread.State: BLOCKED (on object monitor)
    at org.apache.kafka.clients.producer.internals.RecordAccumulator.append(RecordAccumulator.java:196)
    - waiting to lock <0x00000005c360ac88> (a java.util.ArrayDeque)
    at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:830)
    at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:784)
    at org.springframework.kafka.core.DefaultKafkaProducerFactory$CloseSafeProducer.send(DefaultKafkaProducerFactory.java:170)
    at org.springframework.kafka.core.KafkaTemplate.doSend(KafkaTemplate.java:245)
    at org.springframework.kafka.core.KafkaTemplate.send(KafkaTemplate.java:151)

以及

"kafka-producer-network-thread | producer-1" #79 daemon prio=5 os_prio=0 tid=0x00007f1be46ea800 nid=0x23e2 waiting for monitor entry [0x00007f1c7c8bc000]
   java.lang.Thread.State: BLOCKED (on object monitor)
    at org.apache.kafka.clients.producer.internals.RecordAccumulator.expiredBatches(RecordAccumulator.java:283)
    - waiting to lock <0x00000005c360ab48> (a java.util.ArrayDeque)
    at org.apache.kafka.clients.producer.internals.Sender.sendProducerData(Sender.java:280)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:238)
    at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:163)
    at java.lang.Thread.run(Thread.java:748)

以上问题不知道怎么引起的。