With the recent Bitcoin spam transaction volume, the modified version of bitcoind that counterparty uses (bitcoind-addrindex) will periodically experience responsiveness issues.
The cause of this appears to be a the large mempool size, and we have seen bitcoind-addrindex become unresponsive starting with mempool sizes anywhere from 3,000 to 10,000 entries.
At the moment, the best method to mitigate this problem seems to be adding the following parameters to one’s bitcoin.conf, which will cause your node to ignore most of these spam transactions:
minrelaytxfee=0.00005
limitfreerelay=0
This will greatly slow the growth rate of the mempool, and reduce its size, but does not seem to eliminate the problem at the moment.
We are currently investigating the situation further and working on a more robust solution. Stay tuned for updates.