In this work, we focus on such problems in MP2P information sharing systems with Latent Semantic Indexing.
We consider the two-phase locking (2PL) scheme used in distributed transactional systems  for alleviating the impact of node mobility and frequently disconnection in the MP2P systems and use the SVD-updating proposed in  to overcome the problem of static index mentioned earlier.
1) the development of the mechanism enables the LSI index updates over MP2P networks, which is fully distributed and dynamic;
The node departure from an MP2P network and failure are processed in the same way in CSU, but the node behavior will depend on the node types.
Using mobile devices to communicate with each other directly has been a trend for information sharing and can form an MP2P system.