How to explore ripple ledger? I'm running a ripple node on my own server, and try to conduct some analysis to the balance of all ripple accounts. Thus I need to synchronize the ledgers and analyse them. 

Currently, my server has been running on the consensus ledger, and I found the browser /rocksdb. However, I don't know how to extract the data from that browser. It there any GUI tool or example code to do so?
You can extract the entire last validated ledger as a giant JSON file if you want to. Be patient, it might take a while. Your server has to have an RPC port open with administrative permissions. You can use this command:


  rippled -q json ledger ' { "ledger_index" : "validated",  "expand" : true, "full" : true } ' > ledger.json


Be patient, this will take awhile. And your server may use a bit more memory and CPU when it's running.

When it's done, you'll have a giant file (about 1.7GB as of right now) called ledger.json that contains the entire current ledger. This will contain every account, every XRP balance, every offer, every trust line, every escrow, and so on.