Constant zebra_rpc::methods::get_block_template_rpcs::constants::GET_BLOCK_TEMPLATE_MEMPOOL_LONG_POLL_INTERVAL

pub const GET_BLOCK_TEMPLATE_MEMPOOL_LONG_POLL_INTERVAL: u64 = 5;

When long polling, the amount of time we wait between mempool queries. (And sync status queries, which we do right before mempool queries.)

State tip changes make long polling return immediately. But miners can re-use old work with an old set of transactions, so they don’t need to know about mempool changes immediately.

Sync status changes are rare, and the blocks they download cause a chain tip change anyway.

zcashd waits 10 seconds between checking the state https://github.com/zcash/zcash/blob/420f8dfe38fd6b2465a665324366c2ae14aa98f4/src/rpc/mining.cpp#L626