Understanding the fields “LastSend” and “Lastrecv” in Bitcoin RPC
The Getpeerinfo
RPC request is a key interface provided by Bitcoin Core software to recover information about colleagues connected to your local node. Among the various fields returned, two stand out: LASTSEND
and Lastrecv. These fields seem to describe some kind of date and time record, but what do they really represent? In this article, we will divide the meaning behind these fields and explore their implications for the transmission of P2P messages.
What does "LASTSEND" mean?
TheLastsendfield must contain UNIX's EPOCH (UTC) time (UTC), in which a colleague last sent a transaction. This means that if you are checking the local knot using this method,
LASTSENDwill provide the date and time record when the corresponding transaction was committed.
To further illustrate this concept:
Imagine that you are in a P2P network and send a new block to someone else (let's call thempair a). Once the block is added to the current by your local node, you can check using
Getpeerinfowith the following parameters:
Bash
GETPERINFO PEERADDRESS 1234567890ABCDEF, LASTSEND = 1643723401, LASTRECV = 1643723402
`
Here, the LASTSEND
is defined as 1643723401 (the time in seconds since January 1, 1970: 00:00 UTC) when the transaction was committed by Pareer A. the same way,Lastrecv
would be 1643723414 (the time in seconds Since January, 1970, 00:00 UTC), which is the current date and time record.
What does “LASTRECV” mean?
The Lastrecv
field must contain the time of the time of Unix when a colleague received data from you for the last time. This means that if you are checking the local node using this method, Lastrecv
will provide the date and time stamp when the local node sent or receive the corresponding data.
To put it another way: LASTSEND
shows what happened on the other side (the transaction), while theLastrecv
shows what was happening on your side (your local node shipment/receipt data).
Here is an example:
`Bash
GETPERINFO PEERADDRESS 1234567890ABCDEF, LASTSEND = 1643723401, LASTRECV = 1643723412
`
In this case, LASTSEND
is defined at the moment when Peer has committed it. Meanwhile, the Lastrecv
would be defined as the current date and time record (1643723412), indicating that the local node was receiving data from the Parer at that time.
Implications for transmission of P2P messaging
When using RPC ‘Getpeerinfo’ with these fields, you can make informed decisions about whether a transaction or data has been sent and received. For example:
- If
LASTSEND
is different from zero eLastrecv
for zero, it indicates that the local knot has sent data to peer in recent times (since the last shipping).
- If
LastSend
and Lastrecvare different from zero, it suggests that several pairs have recently exchanged data with you.
- If a field is zero, it may indicate that some type of error or loss occurred during transmission.
In conclusion, theLastSendE
Lastrecv` fields on the Bitcoin Core RPC provide a way to analyze the P2P messaging transmission, checking when each colleague sent and last received data. These values offer valuable information about your local knot activity on the network, helping you refine your strategies to deal with messages and transactions received.