Dynamic participation of nodes, also known as churn, is quite common in P2P networks, and Bitcoin network is no exception. The impact of churn becomes more pronounced when nodes with different roles and functionality exist. In this paper we analyze node churn in Bitcoin network where ordinary nodes generate transaction traffic and distribute and verify blocks, while relay nodes that just distribute blocks, but have a larger number of connections. We use the tools of probabilistic analysis and Markov chains, and show that churn of relay nodes has a higher impact on traffic performance than that of ordinary nodes. We introduce two different Continuous Time Markov chains (CTMC) for ordinary and relay nodes to model each type of node’s behavior separately. Our results indicate that node sleep impacts the performance more in networks where the proportion of relay nodes is lower, and also that block and transaction delivery times are higher in those cases. Also, we find that the time needed for a node to synchronize upon rejoining the network after sleep is dominated by the time required for block and transaction verification.

节点的动态参与（也称为搅动）在P2P网络中非常普遍，比特币网络也不例外。当存在具有不同角色和功能的节点时，流失的影响会更加明显。在本文中，我们分析了比特币网络中的节点搅动，其中普通节点生成交易流量并分配和验证区块，而中继节点仅分配区块，但具有大量连接。我们使用概率分析和马尔可夫链的工具，表明中继节点的搅动对流量性能的影响比普通节点高。我们为普通节点和中继节点引入了两个不同的连续时间马尔可夫链（CTMC），以分别对每种类型的节点行为进行建模。我们的结果表明，节点睡眠在中继节点所占比例较低的网络中对性能的影响更大，并且在这些情况下，阻塞和事务传递时间也更长。此外，我们发现，节点在睡眠后重新加入网络后进行同步所需的时间主要由阻止和事务验证所需的时间决定。