# Atomic operations on Broker store **URL:** \ **Category:** Zeek\ **Created:** [July 18, 2017, 9:56am UTC](https://community.zeek.org/t/atomic-operations-on-broker-store/4949 "2017-07-18T09:56:53Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Bencteux\_Jeffrey](https://avatars.discourse-cdn.com/v4/letter/b/f17d59/32.png) [@Bencteux\_Jeffrey](https://community.zeek.org/u/Bencteux_Jeffrey)\ **Post date:** [July 18, 2017, 9:56am UTC](https://community.zeek.org/t/atomic-operations-on-broker-store/4949/1 "2017-07-18T09:56:53Z")
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hi all, I am playing around with Broker framework and I am having some trouble trying to share elements such as set or table between multiple instances of Bro. What I am doing follows : \* A master store script creates a table and add it to the store \* A frontend store script retreive the table, add elements to it and push it back to the store I got strange results doing that such as only one element I was trying to add was added (never the same) so I suspected the problem was concurrency and that my operations were not atomic. Indeed, what happens it that every call to my function in the slave script do not retreive an up-to-date table. Retreiving and adding a new element to a table is not an atomic operation and no function in the API is defined to do it in one call. If I do the same test with Broker::add\_to\_set() with a set instead of a table it works. And it seems that it is because it is implemented as an atomic operation in aux/broker/src/store/frontend.cc. Any idea how to that with a table with existing functions? Or does it needs further developments? If so, any hints on how to implement that? Here is the Bro scripts I used (debug prints removed) : master.bro: @load base/frameworks/broker @load broker\_wrapper const broker\_port: port = 6666/tcp &redef; redef exit\_only\_after\_terminate = T; global h: opaque of Broker::Handle; event bro\_init() {     Broker::enable();     Broker::listen(broker\_port, "127.0.0.1");     h = Broker::create\_master("test\_store");     WRAPPER::broker\_table\_create(h, "test"); } event Broker::incoming\_connection\_established(peer\_name: string) {     print "Conn established: ", peer\_name; } frontend.bro: @load base/frameworks/broker @load broker\_wrapper const broker\_port: port = 6666/tcp &redef; redef exit\_only\_after\_terminate = T; global h: opaque of Broker::Handle; event bro\_init() {     Broker::enable();     Broker::connect("127.0.0.1", broker\_port, 1secs); } event Broker::outgoing\_connection\_established(peer\_address: string,                               peer\_port: port,                         peer\_name: string) {     print "Conn established: ", peer\_address, peer\_port, peer\_name;     h = Broker::create\_clone("test\_store");     WRAPPER::broker\_table\_insert(h, "test", Broker::data("one"), Broker::data("this"));     WRAPPER::broker\_table\_insert(h, "test", Broker::data("two"), Broker::data("is"));     WRAPPER::broker\_table\_insert(h, "test", Broker::data("three"), Broker::data("sparta")); } event Broker::outgoing\_connection\_broken(peer\_name: string, peer\_port: port) {     print "Connection closed by remote peer";     terminate(); } broker\_wrapper.bro: module WRAPPER; export {        global broker\_table\_create: function(h: opaque of Broker::Handle, name: string);        global broker\_table\_insert: function(h: opaque of Broker::Handle, name: string, key: Broker::Data, val: Broker::Data); } function broker\_table\_create(h: opaque of Broker::Handle,                  name: string) {     local tab = Broker::table\_create();     Broker::insert(h, Broker::data(name), tab); } function broker\_table\_insert(h: opaque of Broker::Handle,                  name: string,                 key: Broker::Data,                 val: Broker::Data) {     # look for table with name 'name'     when (local res = Broker::lookup(h, Broker::data(name)))     {         # insert element "key" = "value" into table         local status = Broker::table\_insert(res$result,                         key,                         val);                         print res$result;         # insert table back into store         Broker::insert(h, Broker::data(name), res$result);     }     timeout 10sec     {         print fmt("timeout broker\_table\_insert: %s key: %s val: %s", name, key, val);     } } I also did a second test: If I try to add an element to a set, then test its existence in it with Broker::set\_contains() and it appears not to be in in the set. Any idea why? Any help is welcome! - -- Jeffrey BENCTEUX ANSSI/COSSI/DTO/BSD ---
**Author:** ![robin](https://yyz1.discourse-cdn.com/flex011/user_avatar/community.zeek.org/robin/32/599_2.png) [@robin](https://community.zeek.org/u/robin)\ **Post date:** [July 22, 2017, 2:43pm UTC](https://community.zeek.org/t/atomic-operations-on-broker-store/4949/2 "2017-07-22T14:43:08Z")
Hi Bencteux, You are exactly right: the table operations aren't atomic currently (i.e., they don't happen server-side). Set manipulations are. The main difference is that for sets there are explicit store operations for inserting/removing elements, whereas for tables there are not. I don't think there's a particular reason that Broker doesn't offer table operations. We are working on a 2nd-gen Broker API currently which simplifies usage quite a bit overall. It doesn't have table operations either yet (nor set operations in fact) but I'm planing on adding them shortly. If you want to track progress there, it's in the topic/actor-framework branch. This work shouldn't take very long anymore to get ready. Robin ---
**Author:** ![robin](https://yyz1.discourse-cdn.com/flex011/user_avatar/community.zeek.org/robin/32/599_2.png) [@robin](https://community.zeek.org/u/robin)\ **Post date:** [July 26, 2017, 12:30am UTC](https://community.zeek.org/t/atomic-operations-on-broker-store/4949/3 "2017-07-26T00:30:22Z")
I stand corrected: it actually did have them already, the API just made it easy to miss. I've now added explicit methods for set/table/vector manipulations to the store API in that branch branch (Note that they aren't accessible from the Bro side yet, that'll come shortly). Robin ---
**Author:** ![system](https://canada1.discourse-cdn.com/flex011/uploads/zeek/original/1X/f09d732bc2cc7c7cc7e35db67cf4e1d5233ce7a7.png) [@system](https://community.zeek.org/u/system)\ **Post date:** [May 6, 2022, 3:45pm UTC](https://community.zeek.org/t/atomic-operations-on-broker-store/4949/4 "2022-05-06T15:45:08Z")