raspberry pi
if we can compile it for that, of course...
I'd suggest just testing it on the environment that you intend to use it
Additionally, it's not designed to "bootstrap" by downloading the database from another node; it instead downloads the most recent backup of the database (eg, from S3) and then synchronizes the most recent commits from a peer. (This is because each node only keeps the most recent N commits, not all commits back to the start of time.)
"rebooting", how long does that take?
managed to advance in compilation a little, it was missing paths to PCRE libraries (at least mine)... stuck now in another place
Undefined symbols for architecture x86_64:
"pcrecpp::RE::Init(std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, pcrecpp::RE_Options const)", referenced from:
SParseHTTP(char const, unsigned long, std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, std::map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, SString, STableComp, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, SString> > >&, std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&) in libstuff.a(libstuff.o)
BedrockPlugin_Jobs::_isValidSQLiteDateModifier(std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) in libbedrock.a(Jobs.o)
BedrockPlugin_MySQL::onPortRecv(STCPManager::Socket*, SData&) in libbedrock.a(MySQL.o)
ld: symbol(s) not found for architecture x86_64
"pcrecpp::RE::Init(std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, pcrecpp::RE_Options const)", referenced from:
SParseHTTP(char const, unsigned long, std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, std::map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, SString, STableComp, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, SString> > >&, std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&) in libstuff.a(libstuff.o)
BedrockPlugin_Jobs::_isValidSQLiteDateModifier(std::cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) in libbedrock.a(Jobs.o)
BedrockPlugin_MySQL::onPortRecv(STCPManager::Socket*, SData&) in libbedrock.a(MySQL.o)
ld: symbol(s) not found for architecture x86_64
Hi. I am new to Bedrock -- I find the points for it quite justified, so am thinking of using it for my project. However, I have the following situation -- and I hope some guru here would let me know if that is possible. I want to give out an sqlite database to anyone who wants to read it from their part of the world -- So I want a master node with a set of readonly slave nodes.. That is the kind of distribution of the data I want. Basically, writing into the database would be only from the master (or some set of known nodes); but only reading should be possible on other nodes. Is this kind of distribution architecture possible with Bedrock? Thanks in advance.
@teamtad_twitter Yes, that's exactly how the design currently works! At any point in time there is one leader, and any number of followers. The leader is elected by a quorum of "full nodes" -- ie, anybody who you designate as a viable leader. But you can also designate any number of permanent followers, and thus they will not participate in the leader election (and will never become leaders). Rather, they will remain permanently read-only followers that escalate any attempt to write to the leader.
If the goal is to further constrain followers to not even escalate write commands to the leader, that isn't something currently supported out of the box, but would be pretty easy to do by creating a custom version of the
DB plugin to make leaders just refuse writes escalated from permanent followers.
@teamtad_twitter Here's the code for the entire DB plugin -- as you can see it's pretty small: https://github.com/Expensify/Bedrock/blob/master/plugins/DB.cpp
Currently it has makes only a cursory attempt to determine if the query is a write before escalating it from the follower to the leader: https://github.com/Expensify/Bedrock/blob/master/plugins/DB.cpp#L59 This is because it's not currently designed to be deployed into an "uncontrolled" environment where one of the nodes is less trusted than others.
I would suggest inserting some check here to see if the query tried to write anything: https://github.com/Expensify/Bedrock/blob/master/plugins/DB.cpp#L130 And if it did, then check to see if the peer who escalated the command is a
Permafollower, such as shown here: https://github.com/Expensify/Bedrock/blob/cf2c36027f569df277d3f97ea08ff8a917ad014a/sqlitecluster/SQLiteNode.cpp#L370
As far as how to make the plugin itself, to start I'd suggest just cloning the Bedrock repo and copying
DB.cpp to a new file SecureDB.cpp in /plugins -- that'll ensure it just compiles easy. Later when you have proven it out, you'll likely want to move your SecureDB.cpp plugin into your own private repo, but I'd suggest skipping that to start.
Once you make the
SecureDB plugin, launch Bedrock with the -plugins SecureDB parameter to enable it (and notably, don't enable DB, as that doesn't have the security check you want)
As far as how to actually launch the various nodes of the cluster, a page on that is here: https://bedrockdb.com/multizone.html
It doesn't explicitly talk about how to configure a
Permafollower, but it is as simple as making the -priority of the follower 0 in the follower's command line, and then adding ?Permafollower=true to the node definition in -peerList on all of the full nodes. So, like -peerList node1:9001,node2:9002?Permafollower=true would indicate that node2:9002 is a Permafollower. This is necessary to configure on the leader as well as the follower, because obviously the leader can't trust the follower to advertise its own permafollower status (given that you are using this to identify "untrusted" nodes).
That's a lot of information, but should give you some tips on how to get started. Good luck!
@quinthar Pardon me for asking a trivial question. I tried creating the SecureDB.cpp as suggested that is needed in this logic (I hope I located it in the right location)
if (SStartsWith(upperQuery, "INSERT ")) {
if(peer->params["Permafollower"] == "true") {
STHROW("400 Unauthorized");
} else
response["lastInsertRowID"] = SToStr(db.getLastInsertRowID());
}
... but sadly, am having trouble getting the code to understand "peer" variable
I tried this
Peer* peer = getPeerByID(command.initiatingPeerID);
(and I included some .h files at the top of the code)
This is in the BedrockPlugin_DB::processCommand(...) function but does not compile (that is how I came to know about "peer" variable) .
My C++ is quite rusty and I have not fully gone thru the code -- just kind of intuitively understanding what is to be done.
i'm looking for something that supports SQL read/write queries across multiple machines. it's okay that the sync is a bit delayed, but i need immediate read/write at least to the local DB.
i tinkered a bit with rqlite, but realised that it only allows write to the leader/master node. in my application, i expect significant latency between machines, so this will be a problem..
am i correct in understanding that bedrock allows both read/write to local db, and synchronisation happens in the background?
also, would it be possible to use bedrock as a C/C++ library, similar to what sqlite3 provides?
thanks in advance for help :)
Hi all, I currently run a Discord bot with a SQLite backend database. It was working fine until I enabled sharding, meaning there are multiple threads writing/reading from the same SQLite database. I've enabled WAL mode however I still get SQLITE_BUSY error codes.
I stumbled upon Bedrock, so I figured I could give it a shot. I was able to build and run Bedrock successfully, pointing to my existing SQLite file, however, because there's no Java SDK for Bedrock I decided to give the MySQL plugin a shot. This is where the horror story starts, I'm only able to make SQL queries by connecting to Bedrock via the MySQL CLI client, but not if I'm connected via my bot using the ORM.
Am I out of luck here?
I hope this channel can help me: I just created Expensify/Bedrock#788
The tests pass and it is running, but it doesn't seem to matter what I send on 8888, I get no response. Any advice?
$ nc localhost 8888
SELECT 1;
Query: SELECT 1;
Query:
SELECT 1;All with no response
Lmk the actual compilation errors
@lkm1321_gitlab Sorry for the delay -- yes, all writes are (currently) escalated to the leader. But all reads are done locally. But yes, there's a C++ "Plugin" interface. Here's a really basic example: https://github.com/Expensify/Bedrock/blob/master/plugins/DB.cpp
@dinedal Can you check
/var/log/syslog to see if any errors are being output? Also, what is the exact command line you are running?
Here's a gist if you're interested in adding it. I haven't had a chance to go over it closely but it worked for me https://gist.github.com/zacharywhitley/3d159d3c78a49b54e2fbbe51b79b128a
I was trying to get to work on embedded system
g++-9 -o bedrock .build/main.o -Lmbedtls/library -L/Bedrock -rdynamic -lbedrock -lstuff -ldl -lpcrecpp -lpthread -lmbedtls -lmbedx509 -lmbedcrypto -lz
/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(SLog.o): in function
/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(libstuff.o): in function
/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(libstuff.o): in function
/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(SSignal.o): in function
/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff/SSignal.cpp:157: undefined reference to `backtrace_symbols_fd'
collect2: error: ld returned 1 exit status
make: * [Makefile:114: bedrock] Error 1
/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(SLog.o): in function
SLogStackTrace()':
/Bedrock/libstuff/SLog.cpp:10: undefined reference tobacktrace'/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(libstuff.o): in function
SGetCallstack[abi:cxx11](int, void* const*)':
/Bedrock/libstuff/libstuff.cpp:107: undefined reference tobacktrace_symbols'/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(libstuff.o): in function
SException::SException(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int, bool, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, SString, STableComp, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, SString> > > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
/Bedrock/libstuff/libstuff.cpp:95: undefined reference tobacktrace'/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff.a(SSignal.o): in function
_SSignal_StackTrace(int, siginfo_t*, void*)':
/Bedrock/libstuff/SSignal.cpp:151: undefined reference tobacktrace'/usr/lib/gcc/x86_64-alpine-linux-musl/9.3.0/../../../../x86_64-alpine-linux-musl/bin/ld: /Bedrock/libstuff/SSignal.cpp:157: undefined reference to `backtrace_symbols_fd'
collect2: error: ld returned 1 exit status
make: * [Makefile:114: bedrock] Error 1
just testing or are we SOL for musl?
Hi! I created a super minimal Docker image for Bedrock, it's less than 6MB. If anyone's interested it's available at https://hub.docker.com/r/jveres/bedrock-xsim.