In a private Ethereum network, transactions get submitted to the network via a single RPC node. If the RPC node crashes at some point, is there a possibility of loss of transactions that are in its mempool and haven't been propagated yet to the other nodes? Since mempool is in node memory, after RPC node recovery those transactions are supposed to be lost permanently from the network?
If the RPC node crashes at some point, is there a possibility of loss of transactions that are in its mempool and haven't been propagated yet to the other nodes?
Yes.
Until you 1) receive a block with your transaction 2) are sure about the fact that the network has accepted this block, you cannot know if your transaction is propagated or included in the chain.