broken pipe and request sent errors

[youngkylejan]

I have a zeromq subscriber to zmqpubhashblock event. when i receive a new block_hash, i will use the rpc proxy to call 'getblock' with the block_hash parameter. the first time will successfully return correct result. but when the proxy call getblock with other block hashes after the first time, i will get broken pipe and request sent exception. why?