`ipfs dht get <key>` stucks without returning any result

Help Kubo
1

I tried to use the ipfs dht get <key> command to see what exactly does it do, but it just stucks without returning any value!
I used verbose mode to see what’s going on, I got a lot of repeated messages that I can’t understand and I couldn’t find explanations in the documentation, Like adding peer to query: <peer.ID SgKdrb> with a very short peerId! and dialing peer: <peer.ID duMrvC> and an error messages like error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID a15XHc> dial attempt failed: context deadline exceeded
What the ipfs dht get <key> command supposed to return? from the documentation it says it outputs best value for the given key but what does it mean by that? the value is supposed to be the _NodeId_s who are providing the content or the value of the content?
Can you explain the meaning of the verbose output of the command, please?

$ ipfs dht get -v QmcZojhwragQr5qhTeFAmELik623Z21e3jBTpJXoQ9si1T
11:43:09.333: adding peer to query: <peer.ID SgKdrb>
11:43:09.333: adding peer to query: <peer.ID P5RWqK>
11:43:09.333: adding peer to query: <peer.ID dM5Syi>
11:43:09.333: * querying <peer.ID SgKdrb>
11:43:09.333: * querying <peer.ID dM5Syi>
11:43:09.333: * querying <peer.ID P5RWqK>
11:43:09.625: * <peer.ID SgKdrb> says use <peer.ID dDe6Su> <peer.ID NxuDte> <peer.ID VFZPvH> <peer.ID X4Dedg> <peer.ID eGnwnW> <peer.ID eMFNuR> <peer.ID TwvAzE> <peer.ID VGfj36> <peer.ID a15XHc> <peer.ID WuBNG2> 
11:43:09.625: adding peer to query: <peer.ID dDe6Su>
11:43:09.625: adding peer to query: <peer.ID NxuDte>
11:43:09.626: adding peer to query: <peer.ID VFZPvH>
11:43:09.626: adding peer to query: <peer.ID X4Dedg>
11:43:09.626: adding peer to query: <peer.ID eGnwnW>
11:43:09.626: adding peer to query: <peer.ID eMFNuR>
11:43:09.626: adding peer to query: <peer.ID TwvAzE>
11:43:09.626: adding peer to query: <peer.ID VGfj36>
11:43:09.627: adding peer to query: <peer.ID a15XHc>
11:43:09.627: adding peer to query: <peer.ID WuBNG2>
11:43:09.627: dialing peer: <peer.ID dDe6Su>
11:43:09.627: * querying <peer.ID NxuDte>
11:43:09.635: * <peer.ID dM5Syi> says use <peer.ID WevMU2> <peer.ID WsvzSc> <peer.ID SYXZz6> <peer.ID fMb1VC> <peer.ID TBqBXo> <peer.ID YuVqJz> <peer.ID duMoWQ> <peer.ID br7MTX> <peer.ID Yx1cGs> <peer.ID QvULpP> <peer.ID TUg5e2> <peer.ID WM2Cn3> <peer.ID eR9sJ2> <peer.ID YwSbZc> <peer.ID XJ6kNh> <peer.ID TdxazX> 
11:43:09.635: adding peer to query: <peer.ID WevMU2>
11:43:09.635: adding peer to query: <peer.ID WsvzSc>
11:43:09.636: adding peer to query: <peer.ID SYXZz6>
11:43:09.636: adding peer to query: <peer.ID fMb1VC>
11:43:09.636: adding peer to query: <peer.ID TBqBXo>
11:43:09.636: adding peer to query: <peer.ID YuVqJz>
11:43:09.636: adding peer to query: <peer.ID duMoWQ>
11:43:09.637: adding peer to query: <peer.ID br7MTX>
11:43:09.637: adding peer to query: <peer.ID Yx1cGs>
11:43:09.637: adding peer to query: <peer.ID QvULpP>
11:43:09.638: adding peer to query: <peer.ID TUg5e2>
11:43:09.639: adding peer to query: <peer.ID WM2Cn3>
11:43:09.639: adding peer to query: <peer.ID eR9sJ2>
11:43:09.639: adding peer to query: <peer.ID YwSbZc>
11:43:09.640: adding peer to query: <peer.ID XJ6kNh>
11:43:09.640: adding peer to query: <peer.ID TdxazX>
.
.
. 
11:43:17.544: dialing peer: <peer.ID duMrvC>
11:43:17.544: dialing peer: <peer.ID cUQy2P>
11:43:17.544: dialing peer: <peer.ID PQ4yES>
11:43:17.544: dialing peer: <peer.ID V9sUhN>
11:43:17.544: dialing peer: <peer.ID ay3qwH>
11:43:17.544: * querying <peer.ID QBpDhT>
11:43:17.555: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID eMFNuR> dial attempt failed: context deadline exceeded
11:43:17.555: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID eGnwnW> dial attempt failed: context deadline exceeded
11:43:17.555: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID UMtS1c> dial attempt failed: context deadline exceeded
11:43:17.555: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID VGfj36> dial attempt failed: context deadline exceeded
11:43:17.556: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID a15XHc> dial attempt failed: context deadline exceeded
11:43:17.556: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID VFZPvH> dial attempt failed: context deadline exceeded
11:43:17.557: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID c3skSp> dial attempt failed: context deadline exceeded
11:43:17.557: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID aBSuRH> dial attempt failed: context deadline exceeded
11:43:17.558: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID UQDKeF> dial attempt failed: context deadline exceeded
11:43:17.558: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID XQNDaJ> dial attempt failed: context deadline exceeded
11:43:17.560: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID dDe6Su> dial attempt failed: dial tcp4 172.17.0.8:4001: i/o timeout
11:43:17.560: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID YG5Sgb> dial attempt failed: context deadline exceeded
11:43:17.561: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID XLUBGS> dial attempt failed: context deadline exceeded
11:43:17.568: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID V8eS1T> dial attempt failed: context deadline exceeded
11:43:17.569: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID Zm3xya> dial attempt failed: context deadline exceeded
11:43:17.623: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID aW3RyT> dial attempt failed: context deadline exceeded
11:43:17.711: * <peer.ID QBpDhT> says use <peer.ID SYXZz6> <peer.ID YuVqJz> <peer.ID duMoWQ> <peer.ID SDiUEE> <peer.ID PS3cWu> <peer.ID Yx1cGs> <peer.ID TUg5e2> <peer.ID WhdE2T> <peer.ID WkYprf> <peer.ID X3ocrC> <peer.ID PLa871> <peer.ID cbBRor> <peer.ID WM2Cn3> <peer.ID eFk8h5> <peer.ID bjQTLK> <peer.ID QLESt3> <peer.ID Nypuyu> <peer.ID TdxazX> <peer.ID P5RWqK> 
11:43:17.712: dialing peer: <peer.ID WkPLgX>
11:43:17.712: * querying <peer.ID RWvGqZ>
11:43:17.803: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID Zis2Uh> dial attempt failed: context deadline exceeded
11:43:17.808: error: dial attempt failed: <peer.ID cGnsFX> --> <peer.ID aApUGi> dial attempt failed: context deadline exceeded
11:43:17.820: * <peer.ID doLjVi> says use <peer.ID YU4giB> <peer.ID e7bRcN> <peer.ID WXqVdn> <peer.ID XWUiuj> <peer.ID QBpDhT> <peer.ID aXmg2z> <peer.ID RSVm9d> <peer.ID aMJWoE> <peer.ID buzpeR> <peer.ID Xsj5WK> <peer.ID TtggHg> <peer.ID QVricD> <peer.ID dj7cEE> <peer.ID RTq3F6> <peer.ID WW9hcR> <peer.ID XAhAvf> <peer.ID ak3w1x> <peer.ID PWTWnN> <peer.ID fXERYL>
2

There are a lot of questions in your post, but I’ll try to get to a few of them.

What key are you trying to get? It’s probably not able to find a value for it in the DHT.

These aren’t full peer IDs in the verbose output. They’re just a portion of the peer ID.

An example would be looking up a key of /ipns/publickey and getting the /ipfs/... path it points to as the return value.

Partial reference:
IPFS DHT sharness tests

3

I tried this key QmcZojhwragQr5qhTeFAmELik623Z21e3jBTpJXoQ9si1T which is a key to “Hello, World!” value, I was expecting to get whatever is refering to in the DHT. Is my understanding wrong?

4

This works: https://ipfs.io/ipfs/QmcZojhwragQr5qhTeFAmELik623Z21e3jBTpJXoQ9si1T
Also ipfs get QmcZojhwragQr5qhTeFAmELik623Z21e3jBTpJXoQ9si1T works, it downloads the file with Hello, World! inside.

ipfs dht get returns blank for me as well, not sure what it should give out.

5

Yes exactly! that is why I’m asking what ipfs dht get is supposed to do?

6

Okay, so you were trying an /ipfs/ multihash. AFAIK IPFS doesn’t store the value for a given block’s multihash/key in the DHT – like it does for IPNS keys; rather, it stores pointers to peers that have said they can provide that multihash/key. So trying to use a raw DHT command to lookup a multihash’s value is only going to find peers (which is what I think is in your verbose output, e.g., <peer.ID doLjVi> says use <peer.ID YU4giB> <peer.ID e7bRcN>...). I don’t know if it would be expected for a DHT command to then query the peers for the actual value, but that sounds like it might be outside the scope of a vanilla DHT value get operation: ipfs get, ipfs cat, etc.

I am a bit confused though because the abbreviated peer IDs shown in the verbose output don’t seem to be the same ones that show up in ipfs dht findprovs.

Doing DHT lookups using ipfs dht get /ipns/... seems to be supported, though. If you look at the ipfs dht put helptext, we can see that it explicitly states the /ipns keytypes are the only ones that are currently supported; so it might make sense that ipfs dht get doesn’t explicitly support any other keytypes at this point, either.

You may only use keytypes that are supported in your ipfs binary: currently
this is only /ipns. Unless you have a relatively deep understanding of the
go-ipfs routing internals, you likely want to be using ‘ipfs name publish’ instead
of this.

Reference
Understanding how the DHT is implemented (not sure how current it still is)
go-ipfs/dht.go

1 Like
7

I think I might be wrong about the soandso says use someotherpeer... messages. I think these are just a regular part of any DHT lookup and those peers aren’t the ones that are providers for /ipfs multihashes.

The last verbose line of an attempt to do ipfs dht get /ipfs/QmcZojhwragQr5qhTeFAmELik623Z21e3jBTpJXoQ9si1T -v results in the line of output below right before it returns. So I don’t think the dht get command supports attempts to lookup /ipfs/ values – which don’t have values that exist in the DHT itself.

07:47:47.871: error: routing: not found
8

I have tested it on ipns by publishing a text file and got a strange value, what could it be :confused:

$ ipfs add testipfs.txt 
added Qmd9wBC35KuHjiaeGYANJgVpCmWLDj3phPS4PFkonYDM69 testipfs.txt
 11 B / 11 B [=====================================================================================================================================================================================] 100.00%

$ ipfs name publish Qmd9wBC35KuHjiaeGYANJgVpCmWLDj3phPS4PFkonYDM69
Published to QmcGnsFXHPLCEmjUR3H4KoDHV9vFZPiSPiJrpxa7KHtEuS: /ipfs/Qmd9wBC35KuHjiaeGYANJgVpCmWLDj3phPS4PFkonYDM69
$ ipfs dht get /ipns/QmcGnsFXHPLCEmjUR3H4KoDHV9vFZPiSPiJrpxa7KHtEuS

�0��H��?��Y8(�6�4"3�����G�l������!Y��,]P�����M_N:<�F��'t�W��"2019-01-27T04:38:59.268938606Z(:��0�"0h��z�'�)9�V^���٢���kY��cec�����
�{�8�;e"��X��Z��Aež5���g�^JY:��&���K��d��JY\�,�����މ�^k�ʕb�����1Ne
                                                                     d|���F ���Fa`'����,�����z�CŲ}VAXXewwByr�B^���L��R�a]iüס���gۨ���������{�|3�0�\����W24�/I�����Qg�
$ ipfs cat /ipns/QmcGnsFXHPLCEmjUR3H4KoDHV9vFZPiSPiJrpxa7KHtEuS
Hello test
9

Maybe theese peers are those which route the query (the contacted peers in the query process)

10

When you publish something using IPNS with a private/public keypair, the /ipfs/ hash that you want it to point to in addition to some metadata (e.g., sequence number, timestamps, TTL) and a signature. I don’t see the /ipfs/ path in your output, but maybe it’s some kind of encoding issue – since it’s not really meant to be human-readable.

ipfs cat is basically doing two things in this example. Because it’s an /ipns/ address, go-ipfs first has to resolve the IPNS address (e.g., ipfs name resolve /ipns/...) to determine the immutable /ipfs/ path it’s pointing to (basically interpreting what’s returned by ipfs dht get /ipns/.... Then it has to get the content that the /ipfs/ path is pointing to.