MultiChain Developer Q&A - Recent questions tagged streams

New transaction

Wed, 22 Oct 2025 06:45:26 +0000

How do we know if we have a new transaction? i saw in the docs that we are going to use `blocknotify` but I checked the explorer, it doesn't use `blocknotify`.. can you guide me? not a python dev so im having a problem understanding the logic.. I dont want to run a scheduler just to check if there is a new transaction

Cant save public key string on a stream

Thu, 03 Feb 2022 09:16:44 +0000

I'm trying to save a public key string to stream named 'publicKeys', but after the transaction receives any confirmations it turns to null.and txid changes

Inside the stream key it is stored as JSON before it turns "json": null (items quantity remains the same) ->

{

"data": {

"json": {

"publicKey": "-----BEGIN PUBLIC KEY-----\\nMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDLZSCeZqOuZ4cwLEaOgsZa5CJC\\ndjer1xpthZITnAJvXeu1SlFwev0/W182ZqOMHXqHxFYtw4OPGMSUebKoRMqDAa//\\nddm2SfzeEtP4bloYNhQT0KVGUJqgRclt5u0wPik/Sm1eia11ZPnF8j3geXIu42yd\\n1jBO0u2QOuZ2aj3d9QIDAQAB\\n-----END PUBLIC KEY-----\\n"

}

create stream problem

Tue, 21 Dec 2021 04:16:05 +0000

Hello, i tried to create stream but got error code -705 with error message: entity with this name already exists. I tried finding it with getstreaminfo but it said "Stream with this name not found" and error code -708

https://imgur.com/a/8ZFq9zv

How Stream Read Restrictions work?

Fri, 15 Oct 2021 03:49:24 +0000

Enterprise nodes can use read-restricted streams, in order to publish and retrieve data that is only visible to nodes with the appropriate permissions.

The on-chain streams full data is stored inside the blockchain which every node has a copy of. So the "hacker" without Read permission can read streams from local disk.

Can you explain the principle of "Stream Read Restrictions"?

Thanks.

revoke read permissions not working

Mon, 20 Sep 2021 14:02:52 +0000

I have used the steps for revoking read permissions for one stream created in which I have stored some data.As per site directions at https://www.multichain.com/getting-started/ section 5, the moment the permissions are revoked, the data should not be seen on the second server, but it is seen always irrespective. Steps server 1 are

- create stream store1 '{"restrict":"read,write"}'

- publish store1 id_123456 '{"json":{"source":"Singapore","destination":"Los Angeles"}}' offchain

- publish store1 id_234567 '{"json":{"source":"Rotterdam","destination":"New York"}}' offchain

- grant 1K5FhCZgZXs7GPDiE5mz8udRCyuWFbaMgbWXMj store1.read (## to grant the second server read permissions and after this i am able to see the data at second server##)

- revoke 1K5FhCZgZXs7GPDiE5mz8udRCyuWFbaMgbWXMj store1.read

but after this step too....I am able to read the data at second server..

where I am doing wrong?

Can a server create stream object without any connected node??

Sun, 11 Jul 2021 10:19:30 +0000

Is it obligatory for a server to be connected with a second node before creating a stream or asset object??

OR

Can a server create stream or asset object in standalone mode as well??

is there any dApp example/tutorial to connect in streams?

Thu, 29 Apr 2021 05:34:38 +0000

Hi

where can i find some sample/tutorials to connect to streams via programming languages (or any dApps)?

thanks

How to increase the synchronisation speed ?

Thu, 01 Oct 2020 13:46:41 +0000

We have a business case where we have to frequently write and query multichain streams. To improve the performance, we are writing to a primary node and querying to a secondary node of blockchain network.

But the problem is that when primary node is writing, sync speed is almost 1 block per minute. And when primary node is idle it's still 3 blocks per minute. Sometimes it takes weeks for secondary node to catch up which is not idle for our business case where customers can query the data within 2-3 days of writing.

Our customers are little unhappy with this situation. Please suggest, is there is any solution to increase the speed of syncing or if there is any other solution to this problem.

Our blockchain has around 4,00,000 blocks currently.

How can I publish mutliple data entries in my POE stream?

Mon, 03 Aug 2020 16:36:52 +0000

So I want to store a file hash, user's full name, address, phone number and MAC adress on my stream and then be able to look up if the file exists by looking for the stored file hash, how should I proceed about this?

liststreamkeys in filtercode.

Thu, 16 Apr 2020 02:04:49 +0000

I'm trying to implement my own filter code. In which I want to use liststreamkeyitems as function. since it needs two parameters stringName and keyName. So I tried using it as, liststreamkeyitems("stream1","key1"). Key1 is the key preset in stream1. So while executing this command, it is showing me error as lisstreamkeyitems is undefined. So to know the details of error I tried using teststreamfilters but there also I'm getting some syntacterror .

So I would like to request you if you could take any demo example and show me how to use teststreamfilters command and please also let me know the way I'm using liststreamkeyitems("stream1","key1"), is right or not?

Testfilterstream executed command:

teststreamfilter "function filterstreamitem(){ var item= getfilterstreamitem(); if(item.keys.length<2) return 'At least two keys required';}" "3e0849da9671563be8d71fccf5f33b1c9aeacd681a354fc98350c874e867136c"

O/P error:

Error parsing JSON:function filterstreamitem(){ var item= getfilterstreamitem(); if(item.keys.length<2) return 'At least two keys required';}

Since I was getting above error I tried using runstreamfilter,

runstreamfilter df1 "3e0849da9671563be8d71fccf5f33b1c9aeacd681a354fc98350c874e867136c"

But the output i got is,

Stream input is not found in this transaction

Why I'm getting above error is it bcz i have not passed vout in above line but how can i even pass vout i have not created transaction i have created stream1, which is already created and all i have is its transaction id. In stream how can we get vout?

Check the df1 code:

function filterstreamitem() { var item = getfilterstreamitem(); var keyinfo=liststreamkeyitems(item,"key1");var data=keyinfo.data;if(data>50) return "successful";else return "unsuccessful";}

did I use liststreamkeyitems function properly??

Why do I sometimes get a stream publish error ?

Tue, 18 Feb 2020 08:47:21 +0000

I have used Multichain for years, but all of a sudden I now (starting this morning, after an application restart) receive the following error from time to time:

"this transaction was rejected. This may be because you are sharing private keys between nodes, and another node has spent the funds used by this transaction."

I have two Multichain nodes sharing a private key. They write very little to the blockchain, at most once per second. I only get the error on one of the nodes (and never on the other node), on about 50% of all transactions.

I use Multichain version 1.0.8. The multichaind process has not been restarted for over a year.

Both nodes write to streams, and sometimes to the same stream. They only write one single-transaction at a time.

The written JSON is small, about 1KB.

Why do I get this error?

The error has been reported earlier (https://www.multichain.com/qa/15147/publish-data-error), but there seems to have been no resolution for that.

But Where should i enter my code?

Mon, 27 Jan 2020 01:45:23 +0000

I have read document's smart filters part but i actually wanted each and every step to run my code. Like how should i add my code in command line. There it's written that java-script engine is already embedded. But in which location i have to add java-script code? How should i check that it is working properly? All these things i wanted to know. Can anyone please guide me? And also i want to know more about smart filters. So is there any article or research paper which can be helpful to me to know smart-filters in detail?

Stream Nature

Sun, 12 Jan 2020 15:56:05 +0000

Being Stream Item is a regular transaction, Is the stream itself has it's own chain with a blocks which contain items[transactions]. For Ex. in https://www.multichain.com/getting-started/ stream1 is a totally different chain than chain1? if not how to make sure that those items are on that chain if I have multiple chains.
Is number of stream items per block [transactions] is controlled by some way or it depend on the size of items and size of blocks?
I have a use case that requires dealing with a huge amount of data [ encrypted text and files ] and I have 2 proposal can work: one is one stream contains all the data and the other is using multiple streams to deal with those data which is better from the performance and architecture point of view?

Javascript Library/Realtime streaming

Wed, 20 Nov 2019 17:05:00 +0000

Hello Guys,

I am new to multichain, i was getting into multichain, i know nodejs/javascript.
i wanted to build some apps by multichain, i want some steps to get into, also i wanted to ask is it possible to make realtime in multichain apps, like streaming each data that has been inserted to the stream?

Smart contract to transfer an authority of assets to other User.

Wed, 09 Oct 2019 16:42:58 +0000

Basically I just want to implement a smart contract which has some set of rules between two user.Assets can be issued to the other user by digitally signing the contract by both end user (user1: currently owner of asset, user2: Next owner of the Asset).

Generate automatic events on create/update of item/stream so that polling is not required

Fri, 06 Sep 2019 07:09:04 +0000

I have multichain configured on server. So, like in Ethereum, we can create event in the smart contract which can keep listening to events for new actions, likewise, can we subscribe to stream events using Multichain's APIs without explicitely keep polling from subscriber's end?

Avoiding a publish to root stream attack

Tue, 03 Sep 2019 15:56:46 +0000

Hi there,

We have configured a semi-public network with these params :

root-stream-open = true                 # Allow anyone to publish in root stream
anyone-can-connect = true               # Anyone can connect, i.e. a publicly readable blockchain.
anyone-can-send = true                  # Anyone can send, i.e. transaction signing not restricted by address.

We would like to have root stream open but it seems that no native currency fee is charged for publishing.

As this can lead to a rogue publisher sending garbage to the blockchain, is there any way of charging fee to discourage that behaviour?

We noted that there is a minimum-offchain-fee parameter, that could be useful for of-chain data, but would not apply to on-chain data publishing.

Thanks!

publish data error

Tue, 20 Aug 2019 07:31:03 +0000

Now we have 4 nodes A,B,C,D and two streams. And we have created a java project to publish items to stream through JSON. Previously we can publish items to stream no problem and there is already more than two million items. But we often encountered with publishing error recently. Please find following error message.

Error while doing transaction with the blockchain. Code: -26.0 Message: Error: this transaction was rejected. This may be because you are sharing private keys between nodes, and another node has spent the funds used by this transaction.

Stream Confidentiality for PDF etc.

Fri, 09 Aug 2019 10:06:18 +0000

Hello,

I did the instruction https://www.multichain.com/developers/stream-confidentiality/ for Linux.

Unfortunately, this method is only suitable for text files (txt), but I need it format independent.

So, now my question is, how can I send/encrypt other formats like PDF oder MS Word (docx) with this instruction in Linux?
And is there although a possibility to do the same in Windows 8 ?

Thanks in advance for your answer!

Stream confidentiality Description

Fri, 02 Aug 2019 09:54:31 +0000

Hello,

I try encrypted data transmission in multichain (on VM) according to your instructions. (https://www.multichain.com/developers/stream-confidentiality/)

At the moment, I struggle with that part under "Publish an RSA key pair" wich says:

You should see a block of alphanumeric gibberish, surrounded by BEGIN PRIVATE KEY and END PRIVATE KEY lines. This is an RSA private key. Now let’s generate a public key from that, convert it immediately to hexadecimal, store it in the pubkeyhex shell variable, and take a look:

pubkeyhex=$(openssl rsa -pubout -in ~/.multichain/chain1/stream-privkeys/.pem | xxd -p -c 9999)
echo $pubkeyhex

Finally, let’s publish our public key as an unlabelled item in the pubkeys stream, which should return a transaction ID:

multichain-cli chain1 publishfrom pubkeys '' $pubkeyhex

For the line "pubkeyhex=$(openssl rsa -pubout -in ~/.multichain/chain1/stream-privkeys/.pem | xxd -p -c 9999)" I get "Can't open /home/...... for reading, No such file or directory ... unable to load Private Key"

I tried it without the xxd part like: "pubkeyhex=$(openssl rsa -pubout -in ~/.multichain/chain1/stream-privkeys/.pem)", than it says "writing RSA key". So I guess that's ok, because with the following "echo $pubkeyhex" it gives me a public key (BEGIN PUBLIC KEY ....... END PUBLIC KEY).

But the last step from the heading (multichain-cli chain1 publishfrom pubkeys '' $pubkeyhex) returns a long error message (error code: -1) with arguments and examples but I don't see what's wrong...

Do I have to complete this line with an address or something??

Thanks in advance for your help.

Greetings

interoperatibiltiy between community/enterprise chains

Sun, 14 Jul 2019 14:02:06 +0000

we are struggling at a point,

can two or more different Multichains, interact with each other,

Chain one is ABC and having multiple instances

Second chain DEF having multiple instances,

Third GHI is also having multiple nodes

All have a different business nature,

ABC is a financial asset platform,

DEF is more towards the Supply chain

GHI is using more services towards hashing off-chain documents and storing the hash on the chain,

can these three interact in terms of asset transfer and metadata messages, with each other and scale up the network

Stream permission by address

Thu, 04 Jul 2019 03:09:47 +0000

Scenario:
Node A creates a stream "Stream1". I believe only in Enterprise I can block node B from joining?
Let say they have joined, can I control which stream items are visible to node B?

Writing streanm filter with specific function

Wed, 03 Jul 2019 21:23:38 +0000

Hi,

I am looking to create a smart filter that makes sure if you post an item with key value x that the last item on the stream had key value y in order to post it. Is there a way to perform this check? I couldn't follow the API very well to know if there was a good way to make sure. Thanks

Is it possible to remove the "retrieve" keyword from a stream that previously has retrieve?

Mon, 01 Jul 2019 06:38:21 +0000

I just want to confirm that my understanding is correct.

For a node setup in Multichain Community version, the following assumptions are made:

Subscribe command always executes with retrieve for community version .
When subscribed to a stream restricted to offchain data only, all items are automatically retrieved.

After upgrading this same node to Enterprise version:

Trimsubscribe command can be executed to change the behavior of the node's subscription to a stream.
After trimming retrieve parameter from the subscription, the node will no longer retrieve the offchain data automatically. only the onchain hash and metadata will be indexed.
Perviously retrieved offchain items will remain in the node unless running purgestreamitems.
purgestreamitems only purges offchain data on the node that was not published by the node itself.

For nodes running enterprise:

purgestreamitems can be run at any given time, somewhat like clearing a cache.
when retrieving offchain data on demand, is the speed of the transfer from source node to destination node dictated primarily by the connection speed between the two nodes?

Data Retrieval Speed in Streams Versus Asset Transactions

Sat, 15 Jun 2019 14:32:18 +0000

Kindly answer whether data retrieval in streams is faster in terms of time than the retrieving of meta data from an asset transaction? I am saying this after studying the article from https://www.multichain.com/blog/2016/09/introducing-multichain-streams/. You are therefore requested for the confirmation.

How can we use Timestamps in Multichain ?

Sat, 01 Jun 2019 11:41:51 +0000

I am actually using Data Streams for my project. There is a point where i need to timestamp the items that i am publishing to the stream.

as far as i know, each Multichain transaction is timestamped.

However, i need the timestamp to be appended to the metadata of my stream item. so i have 2 questions;

1. How exactly does Multichain ascertain the accuracy of a timestamp ? does it use the PC's time, which can be unreliable and can easily be hacked. or does it use some internet time protocol ? Please elaborate

2. How can a develop access the timestamp at the time of PUBLISHING the item to the stream ? so that we can use it in our steam item's metadata ?

Please let me know at the earliest

Is it possible add metadata to binarycache offchain transaction in a stream?

Fri, 31 May 2019 16:43:30 +0000

Hi,
I'm working saving files using binarycache and publishing it in a stream with the following command via multichain-cli:

publish stream1 key1 '{"cache": "aHAN7Z9jF4S"}' offchain

So the question is:

Is it possible to add metadata with an JSON object and save the JSON object on-chain, and the binary cache off-chain with the same transaction?

getting data from streams

Fri, 17 May 2019 10:30:00 +0000

Hello Multichain,

I have created a stream called users, where each address of the user is stored along with the username. I could get the entire array of objects and check for a purticular user. But I needed a more effecient method

Is there a way by using say Smartfilters we can pass metadata value and get the object out ?

Please let me know

Thanks

Publish Asset details on to the stream

Tue, 14 May 2019 13:21:55 +0000

Hi Multichain,

Is there a way to publish asset details onto the stream???

stream subscription

Fri, 10 May 2019 04:38:19 +0000

Hello Multichain,

I have created a 2 node multichain and I have connected node2 to node1. I would like to know if I create a stream from an address in node 1 can an address from node2 subscribe to it.

thanks

Querying a specific parameter within json stored to a stream

Wed, 01 May 2019 07:54:56 +0000

Good Day,

If I've published a number of parameters to a stream in json format, e.g.

{"method":"publish","params":["Car logbook","REG1231",{"json":{"VIN":"7820D","Date":"01052019","Inspector":"JP211","Station":"OXFORD","Condition":"Satisfactory","Actions":"1A"}}],"chain_name":"nw-469-371-2"}

{"method":"publish","params":["Car logbook","REG9922",{"json":{"VIN":"1001D","Date":"01052019","Inspector":"JP211","Station":"CHARLIE","Condition":"Unsatisfactory","Actions":"2A"}}],"chain_name":"nw-469-371-2"}

{"method":"publish","params":["Car logbook","REG1231",{"json":{"VIN":"7820D","Date":"01052019","Inspector":"JP211","Station":"DELTA","Condition":"Satisfactory","Actions":"1B"}}],"chain_name":"nw-469-371-2"}

Is there a way for me to setup a query that just lists entries for VIN: 7820D ?

At present, I see that it is possible to list items by publisher and key. I'd like to present a web portal with a function that allows me to search and filter results at a granular level, quickly.

Regards,

Zaid

Stream Permissions

Thu, 25 Apr 2019 18:28:46 +0000

I'm looking into streams and wondering how I can set Stream level permissions.

For e.g. How can I say

UserA can write to Stream1 and Stream2

UserB can only read from Stream1

UserC can only read from Stream2

immutability in multichain

Thu, 18 Apr 2019 07:19:36 +0000

Hiii TEAM ,

I am checking immutability of data in multichain so, i have created chain called xyz and inside that stream is 'test' .Also i have publised data in stream using

publish test key173747265616d2064617461

txid:b209239b63a6adc2712063b376e9fa3c20c53c5d73f60a6332e9cd4b907bee92

{

"hash" : "00473f8380ace1f5ac27aba08bcdc855b33aa21f077f257dcc159a8634b63187",

"previousblockhash" : "0074c2a26a616e889284abb5c643552afbcad6c35a0bb92c474db15830fb3fad",

"nextblockhash" : "001c5ebd08cdd5281568ff7db1b08f96a3a3573237b0ecac02626300c1707392"

}

now i have updated data of same key key1
publish test key1 6d7920696d6d757461626c652074657374
tx id:9ef0f983313780b619f0b96427b1c4f8b1f7e005fe6ae5e2ae0fd6f56bcdf36a

{ "hash" : "00f422586204cbfe02211d5cd9639169ec54a52b0e519d912f61305b82dccad2",

"tx[ "cd8dffa2b4ceb34d795586928167dcd6da8925d7f65c4df7cde2a0fac0110ac4",

"9ef0f983313780b619f0b96427b1c4f8b1f7e005fe6ae5e2ae0fd6f56bcdf36a" ],

"previousblockhash" : "000a7a202d4af3cde5c0ffdc2293d020e2c01d447d1ceb0a14c928b340d1f94c",

"nextblockhash" : "00ce30145953c6702c58cb2e6c171791582dc46e4d2e630dcb1a70578305363a"

}

But when i fetch both transaction using getblock api i am getting different different prevblockhash and nextblockhash but not in chain?

and also wanted to understand what is the difference between hash ,prevblockhash and nextblockhash?

How is Metadata created?

Thu, 11 Apr 2019 12:05:55 +0000

I have seen in lot of tutorials of Multichain.
Which contains metadata;
1. Can you please help me understand what is Metadata?
2. How is it created?
3. How does it help is asset transferss

automate the verification of revoked certificates in the stream

Mon, 08 Apr 2019 10:07:20 +0000

hi dears,

i ma building a pKI based on multichain, I want to know if it is possible to make automatic the verification (from other application like browsers or others) of revoked certificates which are already published in the stream; any help please

Cordially

How do I publish textual data on a stream?

Sun, 07 Apr 2019 19:36:27 +0000

I am using

multichain-cli [chainname] publish stream1 [key1] {"text":"hello world"}

(with appropriate chainname and key)

However, it returns

error code: -8
error message:
data should be hexadecimal string or recognized object

(I am using cmd to preform this)

Retriving data fro stream

Sun, 07 Apr 2019 16:01:40 +0000

Hello

I want to retrive data stored in a stream for comparing it using node.js..is there any way to retrive specifically data field in the stream...

getstreamkeysummary condition

Sun, 07 Apr 2019 13:51:16 +0000

Is there any way to apply conditions to a 'getstreamkeysummary'? for example 'status' == 'pedding'

Create permissions - are there different types for streams?

Thu, 04 Apr 2019 21:13:54 +0000

I have a network with 5 nodes. I query the permissions of my "node 5" and it has 'create' permission.

https://paste.pics/c143fb5a46f06df9c7ad116cd42ef464

I try to create a stream on node 5 but receive an error that it does not have create permission on the wallet.

https://paste.pics/8879f7827b73498b5adfec6a4519d598

There is only 1 wallet on this node.

https://paste.pics/a3eecbaa9b17d677f365e9ba0838de72

The seed / first node then grants create permission to node 5 (even though it already seemed to have it):

https://paste.pics/a6ae4e81b5ac23382d970c5ede9cdded

Now, I can create a stream on node 5 successfully:

https://paste.pics/57T7U

I do not understand what is happening here. Why did node 1 need to grant create permission to node 5, if node 5 already seemed to have it?

This happened with all the other nodes as well.

Stream Smart Filter: Get Transaction Information through TxID

Tue, 26 Mar 2019 20:30:23 +0000

While I was developing a Smart Filter I encountered a situation where the streamItem.keys[0] was a transactionID and I had to get information about that transactionID.

Basically, I needed a function

getTransaction :: TxID -> { TransationInfo }

where I could pass a transaction ID and receive more information about that transaction.

Use-Case: The user is posting some data into the stream, referring (through a txID in the key), that this new data is supposed to replace an older item with said ID, and I need to make sure that this old ID exists (and a few other properties as well).

thread_resource_error while reading stream content

Wed, 13 Mar 2019 12:02:30 +0000

Hi Team,

While executing "gettxoutdata" API to read stream content we are getting below error -

EXCEPTION: N5boost16exception_detail10clone_implINS0_19error_info_injectorINS_21thread_resource_errorEEEEE

boost::thread_resource_error: Resource temporarily unavailable

bitcoin in ProcessMessages()

Please note "gettxoutdata" API was triggered using "walletnotifynew".

Please let us know what is the resolution for this issue.

Error in multichaind: malloc(): memory corruption

Thu, 07 Mar 2019 16:44:37 +0000

I have a 3 node blockchain with a stream where I have added 2M items with random data off-chain (images). All the data is persistent, so I can bring down and up nodes without issues.

However, now I get this error when trying to bring up an existing node back using the persistent data it left when it was brought down:

https://gist.github.com/emedina/14cfec01ee898f7557ee4ba17fa60f3a

And I just cannot bring it back again.

Blockchain stops working with 3 nodes using a stream with 2M transactions

Thu, 07 Mar 2019 16:26:18 +0000

I have the following scenario:

1 node that created the blockchain and a stream, which I used to create a stream and add 2M items into it, with random off-chain content (images).
2 nodes that join the blockchain after all the data has been imported through the master node, so on startup they begin to catch up with the master node at their own pace.

At the very beginning when the 2 new joined nodes are initially catching up, I can issue commands to any of the 3 nodes using the multichain-cli tool. For instance, I send this command to the master node and I get the reply back immediately:

multichain-cli ipregister -rpcuser=multichainrpc -rpcpassword=m4lt1ch41nRpC! getaddresses
{"method":"getaddresses","params":[],"id":"85616894-1551974478","chain_name":"ipregister"}
[
"1WTvECnAdMgvXDqMDQeiwXExCfvvMuHwq1HR7S"
]

However, at some point in time, when the volume of data being already synced up grows, the multichain-cli tool stops responding for all the nodes, and as the volume of synced data still grows, the nodes start to degrade dramatically until they just do not respond to commands.

Both 2 nodes join the blockchain through the DNS name of the master and they just subscribe to the stream to be able to find data by key, that's all.

Then I stop everything (without deleting the data) and restart first the master node. It starts to respond again to multichain-cli commands. But when I start again the first of the 2 additional nodes, I start getting this from it:

Node started
mchn: Sending minimal parameter set to 174.16.60.237:8099
receive version message: /MultiChain:0.2.0.6/: version 70002, blocks=28632, us=174.16.138.178:50952, peer=1
Added time data, samples 2, offset +0 (+0 minutes)
mchn: Parameter set from peer=1 verified
Loading addresses from DNS seeds (could take a while)
0 addresses found from DNS seeds
dnsseed thread exit
socket sending timeout: 61s

And then in the master:

Sending minimal parameter set to 174.16.138.178:50952
receive version message: /MultiChain:0.2.0.6/: version 70002, blocks=28627, us=174.16.60.237:8099, peer=7
Added time data, samples 3, offset +0 (+0 minutes)
mchn: Parameter set from peer=7 verified
ResendWalletTransactions()
Sending minimal parameter set to 174.16.138.178:8099
receive version message: /MultiChain:0.2.0.6/: version 70002, blocks=28627, us=174.16.60.237:58276, peer=12
mchn: Parameter set from peer=12 verified

Clearly, the 2nd node degrades just after joining again the blockchain. If I join the 3rd node it gets even worse.

Can we write queries in Multichain like select * from Stream1.key1 where key1.value = “xyz”

Sat, 23 Feb 2019 14:33:38 +0000

Can we write queries in Multichain to retrieve conditional data from streams e.g. select * from Stream1.key1 where key1.value = “xyz”

Stream Smart Filter: Is the file still kept in storage if invalid?

Mon, 18 Feb 2019 21:04:07 +0000

A stream filter is only applied by nodes subscribed to a stream, and so is more efficient, but cannot prevent malicious nodes from publishing invalid data (which will subsequently be ignored by stream subscribers). Note also that transaction filters cannot perform validation of off-chain data, since that data does not appear inside the transaction itself, whereas stream filters can validate both on-chain or off-chain data.

Am I right to assume that "ignored by stream subscribers" means that files deemed invalid by stream rules would be deleted upon arrival by the nodes?

but if make streams items with multiple keys then??

Fri, 08 Feb 2019 14:37:16 +0000

Get last item published in stream

Fri, 08 Feb 2019 13:49:56 +0000

Am new to multichain.. got basic question about retrieving latest items from stream.

Can one relies on 'liststreamitems' with start = '-1' and count ='1' to retreive last published item in stream?
Is it guarantees that last item appended is always the last item publish.

if mining time at one of node took longer time than others, can order of items changes from one node to another. and items orders would differ from order they being actually published?

For example, there 3 publishers (a, b & c) subscribed to certain stream 'testStream'.

if (a) then (b) published new record (item1) to 'testStream'.

could (c) see the same order or it can be swapped due to its mining time or other reason?

how to create a node which can connect to an existing node .

Tue, 05 Feb 2019 17:51:26 +0000

how to create a node which can connect to an existing node . I want all the nodes to sync at the same time and all transactions should be present on all the nodes. In order to create a cluster of nodes for better reliability.

Can you tell me how to clone a node and how two nodes will communicate to each other.?

Who will add block of transactions or streams into chain(i.e., block chain)?

Tue, 05 Feb 2019 08:42:44 +0000

Blockchain data storage

Thu, 17 Jan 2019 10:32:05 +0000

Hello guys,
1)When we say data gets added in block and its added to blockchain what does it mean does it add transaction within block in every node which is in network? or does it mean some thing else?
2)i have read that in multichain 2.0 in single transaction publish items to multiple streams? can you give any example where we can use that?

3) if any node gets crosses limits of storing blocks then by adding additional capacity to node does it affect network runtime params?