1

I am using Geth 1.8.15-stable-89451f7c and starting geth in syncmode "light" starts importing block headers from 0. Is this expected or should it not start from the most recent block?

Following is the command I used to start light client:

geth --syncmode "light" --datadir data --rpc --rpcaddr localhost --rpcapi db,eth,net,web3,txpool --networkid 3711 -unlock 0x88978ac640c6b1e90a1be434af1907c26501543e --password password.txt --nodiscover --verbosity 4

Following are the logs:

INFO [09-17|02:54:07.822] Initialised chain configuration          config="{ChainID: 3781 Homestead: 1 DAO: <nil> DAOSupport: false EIP150: 2 EIP155: 3 EIP158: 3 Byzantium: 4 Constantinople: <nil> Engine: clique}"
INFO [09-17|02:54:07.823] Loaded most recent local header          number=0 hash=854058…668426 td=1
INFO [09-17|02:54:07.824] Starting P2P networking 
WARN [09-17|02:54:07.824] Light client mode is an experimental feature 
DEBUG[09-17|02:54:07.912] Light Ethereum peer connected            id=477834e87a1554ec conn=staticdial name=Geth/v1.8.14-stable-316fc7ec/linux-amd64/go1.10
DEBUG[09-17|02:54:07.912] Received new announcement                id=477834e87a1554ec conn=staticdial number=274403 hash=b3466a…8c1954 reorg=0
DEBUG[09-17|02:54:07.912] Registered new entry                     enode=477834e87a1554ec
DEBUG[09-17|02:54:07.912] Synchronisation started                  id=477834e87a1554ec conn=staticdial
INFO [09-17|02:54:07.912] Block synchronisation started 
DEBUG[09-17|02:54:07.912] Synchronising with the network           peer=477834e87a1554ec eth=63 head=b3466a…8c1954 td=547249 mode=light
DEBUG[09-17|02:54:07.913] Retrieving remote chain height           peer=477834e87a1554ec
DEBUG[09-17|02:54:07.913] Fetching batch of headers                id=477834e87a1554ec conn=staticdial count=1 fromhash=b3466a…8c1954 skip=0 reverse=false
DEBUG[09-17|02:54:07.935] Remote head header identified            peer=477834e87a1554ec number=274403 hash=b3466a…8c1954
DEBUG[09-17|02:54:07.935] Looking for common ancestor              peer=477834e87a1554ec local=0 remote=274403
DEBUG[09-17|02:54:07.952] Fetching batch of headers                id=477834e87a1554ec conn=staticdial count=1 fromnum=0 skip=15 reverse=false
DEBUG[09-17|02:54:07.972] Found common ancestor                    peer=477834e87a1554ec number=0      hash=854058…668426
DEBUG[09-17|02:54:07.993] Directing header downloads               peer=477834e87a1554ec origin=1
DEBUG[09-17|02:54:07.993] Downloading block bodies                 origin=1
DEBUG[09-17|02:54:07.993] Downloading transaction receipts         origin=1
DEBUG[09-17|02:54:08.013] Fetching batch of headers                id=477834e87a1554ec conn=staticdial count=128 fromnum=192 skip=191 reverse=false
DEBUG[09-17|02:54:08.074] Filling up skeleton                      from=1
DEBUG[09-17|02:54:08.215] Fetching batch of headers                id=477834e87a1554ec conn=staticdial count=192 fromnum=1   skip=0   reverse=false
INFO [09-17|02:54:08.259] Stored checkpoint snapshot to disk       number=0      hash=854058…668426
DEBUG[09-17|02:54:08.312] Inserted new header                      number=1      hash=76a1c7…744617
DEBUG[09-17|02:54:08.313] Inserted new header                      number=2      hash=392992…307d46
DEBUG[09-17|02:54:08.313] Inserted new header                      number=3      hash=718ee7…e90c0e
DEBUG[09-17|02:54:08.313] Inserted new header                      number=4      hash=e4aee8…7f4069
DEBUG[09-17|02:54:08.313] Inserted new header                      number=5      hash=50b580…a71ae2
DEBUG[09-17|02:54:08.313] Inserted new header                      number=6      hash=509fb3…ddda0b
DEBUG[09-17|02:54:08.313] Inserted new header                      number=7      hash=0498d6…f27921
DEBUG[09-17|02:54:08.314] Inserted new header                      number=8      hash=4af189…0fd2e7
DEBUG[09-17|02:54:08.314] Inserted new header                      number=9      hash=645807…6bd7c5
DEBUG[09-17|02:54:08.314] Inserted new header                      number=10     hash=c8e384…3b66c8
DEBUG[09-17|02:54:08.314] Inserted new header                      number=11     hash=bfd9cb…a49823
DEBUG[09-17|02:54:08.314] Inserted new header                      number=12     hash=461e0b…583717
4
  • It is expected.
    – Briomkez
    Sep 17, 2018 at 6:12
  • @Briomkez Is this changed recently with latest versions of geth? Could you please confirm? As per this link, it is stated otherwise ethereum.stackexchange.com/questions/17916/…
    – Jith
    Sep 17, 2018 at 6:15
  • @Briomkez, I could see the light client getting crashed when trying to download the entire headers from beginning. The AWS instance where I am trying to run the light node has got only 512 MB Ram. Does it require more memory? I thought this was enough for a light client.
    – Jith
    Sep 17, 2018 at 6:23
  • Maybe you're right (it is possible that it does not start from the beginning) . But the protocol requires that the light nodes downloads ALL the block headers (so that it can eventually ask other peers in the network to provide the information with a given hash).
    – Briomkez
    Sep 17, 2018 at 9:16

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.