I am not aware of any plans to allow replication of data between brokers for data stores that run on the same hosts as the ActiveMQ brokers. Though you may be able to run your clustered NFS processes on the same hosts that the broker is running on, so you could consider that possibility.
Alternatively, you can consider migrating to ActiveMQ Artemis, which does support replication from one broker to another without the need for a shared data store. Artemis is receiving more of the development effort these days, and the vision is that Artemis will eventually replace 5.x entirely, so it may make sense to migrate to it now. Tim On Thu, Jul 8, 2021, 9:14 PM ヤ艾枫o.-- <1169114...@qq.com.invalid> wrote: > Thanks for you reply, The main reason why I don't use NFS is that I need > to ensure the high availability of the NFS cluster or rely on third-party > storage, which will increase my cost. > > The leveldb + zookeeper mode, when building a cluster, can ensure that > each node can store a piece of data, so I do not need to rely on > third-party storage. and I don't need to worry about the stability of > the third-party storage。 > Based on the above considerations, will the community add similar > functions in activemq5. X version > ------------------ 原始邮件 ------------------ > 发件人: > "users" > < > tb...@alumni.duke.edu>; > 发送时间: 2021年7月8日(星期四) 晚上7:50 > 收件人: "ActiveMQ Users"<users@activemq.apache.org>; > > 主题: Re: I have a question about levedb > > > > Thanks for the link. To the best of my knowledge, that particular > experiment never bore fruit and there is no current effort underway to > implement replicated KahaDB. > > Regarding NFS, I agree, I wouldn't run a single NFS server for exactly that > reason. Running your own NFS cluster in clustered mode would be one option > to ensure resiliency. Running a single NFS process in front of a storage > array would be another, but you'd still have availability concerns even > though you've resolved the durability concerns. Another would be a managed > offering such as AWS EFS, which takes all the work off your plate. (I'd use > EFS if it were me.) But yes, a single NFS server writing to local storage > is not what I had in mind, for exactly the reasons you identified, but that > doesn't mean that NFS as a whole isn't a viable option. > > Also note that if your organization already has a resilient NFS service, > you could host your data there rather than build your own just to hold > these KahaDB files. > > Tim > > On Thu, Jul 8, 2021, 12:08 AM ヤ艾枫o.-- <1169114...@qq.com.invalid> > wrote: > > > Hello, you may have misunderstood me. First ,“Can you please provide > the > > link where you saw KahaDB replication discussed?”This is the > website[1] > > Second: > > "In the KahaDB on NFS case, your statement that the data is > unavailable > > when > > a broker fails is inaccurate. Because the data is written to an NFS > share, > > it is readable by many machines, and as soon as a new broker can > acquire > > the lock due to the active broker's failure, the machine that > acquires the > > lock will become the active broker" > > I know what you mean ,when a broker fails ,a new broker can become a > > master. > > but wWhat worries me is that after the server where the NFS storage is > > located goes down, the whole cluster will be paralyzed, > > > > > > > > > > > > > > > > > > 1.https://activemq.apache.org/kahadb-replication-experimental > > <https://activemq.apache.org/kahadb-replication-experimental>>; > > > > > > > > > > > > ------------------&nbsp;原始邮件&nbsp;------------------ > > 发件人: > > > "users" > > > < > > tb...@alumni.duke.edu&gt;; > > 发送时间:&nbsp;2021年7月7日(星期三) 晚上8:08 > > 收件人:&nbsp;"ActiveMQ Users"<users@activemq.apache.org&gt;; > > > > 主题:&nbsp;Re: I have a question about levedb > > > > > > > > Can you please provide the link where you saw KahaDB replication > discussed? > > I suspect that the content is very out of date since I'm not aware of > any > > current development effort to implement replicated KahaDB. > > > > To the best of my knowledge, the out-of-the-box data store options > > available to you are KahaDB on NFS and JDBC (with a number of database > > engines supported). You can also use pluggable storage lockers[1] to > > decouple the locking technology from the storage technology if > necessary > > (e.g. for NFSv3 whose locks are not supported). > > > > In the KahaDB on NFS case, your statement that the data is > unavailable when > > a broker fails is inaccurate. Because the data is written to an NFS > share, > > it is readable by many machines, and as soon as a new broker can > acquire > > the lock due to the active broker's failure, the machine that > acquires the > > lock will become the active broker, read the data file, and begin > receiving > > and delivering messages from/to clients. So I think your assessment > that > > replicated LevelDB is necessary to get resilience without having to > use a > > SQL database wasn't accurate and led you down the wrong path. You > should > > use KahaDB on NFSv4. > > > > 1. https://activemq.apache.org/pluggable-storage-lockers > > > > Tim > > > > On Wed, Jul 7, 2021, 12:13 AM ヤ艾枫o.-- <1169114...@qq.com.invalid > &gt; > > wrote: > > > > &gt; I learned from the official website that the master-slave > modes > > currently > > &gt; supported are "shared file system master slave" and "JDBC > master > > slave". > > &gt; > > &gt; > > &gt; "Shared file system master slave": the mode depends on > shared files > > and > > &gt; only exists on one node. If the host of the node is down, the > > master-slave > > &gt; mode will be invalid > > &gt; > > &gt; > > &gt; "JDBC": the mode needs to rely on the database, which costs > a lot. At > > the > > &gt; same time, the database needs to have the master / slave > mode, so > > that the > > &gt; cluster can be robust. > > &gt; > > &gt; > > &gt; So I had to use activemq+zookeeeper to avoid shared file > storage and > > JDBC > > &gt; database storage > > &gt; > > &gt; We learned from the official website that masterslave > &amp;gt; kahadb > > &gt; replication (experimental) is in the experimental stage. Is > this mode > > &gt; similar to the previous ActiveMQ + zookeeper + leveldb and > > independent of > > &gt; shared files?At the same time, when can we go online to > provide > > services > > &gt; > > &gt; > > &gt; > ------------------&amp;nbsp;原始邮件&amp;nbsp;------------------ > > &gt; 发件人: > > > &gt;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; > > "users" > > > &gt;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; > > < > > &gt; tb...@alumni.duke.edu&amp;gt;; > > &gt; 发送时间:&amp;nbsp;2021年7月5日(星期一) 晚上7:40 > > &gt; 收件人:&amp;nbsp;"ActiveMQ Users"<users@activemq.apache.org > &amp;gt;; > > &gt; > > &gt; 主题:&amp;nbsp;Re: I have a question about levedb > > &gt; > > &gt; > > &gt; > > &gt; Let me strengthen the statement made by Justin. > > &gt; > > &gt; The decision to deprecate and soon remove LevelDB was made > because > > there > > &gt; was no developer willing/able to maintain the code and no > member of > > the > > &gt; mailing list willing/able to answer questions, even basic > ones, on > > this > > &gt; mailing list. > > &gt; > > &gt; If you aren't prepared to answer your own questions by > reading the > > source > > &gt; code without any support from this mailing list, and to > debug and fix > > any > > &gt; bugs you encounter in the Scala code, don't use LevelDB. > > &gt; > > &gt; And even if you're willing to do those things, you'll be > unable to > > upgrade > > &gt; ActiveMQ to 5.17.0 or later, even if there are security > > vulnerabilities or > > &gt; other compelling reasons to upgrade. I strongly encourage > you to > > switch to > > &gt; KahaDB immediately. > > &gt; > > &gt; Tim > > &gt; > > &gt; On Sun, Jul 4, 2021, 11:45 PM ヤ艾枫o.-- > <1169114...@qq.com.invalid > > &amp;gt; > > &gt; wrote: > > &gt; > > &gt; &amp;gt; I know the levedb was removed. > > &gt; &amp;gt; but now I use zookeeper + ActiveMQ to build > master-slave > > mode。 > > &gt; &amp;gt; > > &gt; &amp;gt; > > &gt; &amp;gt; > > &gt; &amp;gt; > > &gt; &amp;gt; > > > ------------------&amp;amp;nbsp;原始邮件&amp;amp;nbsp;------------------ > > &gt; &amp;gt; 发件人: > > &gt; > > > &amp;gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; > > &gt; "users" > > &gt; > > > &amp;gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp; > > &gt; < > > &gt; &amp;gt; jbert...@apache.org&amp;amp;gt;; > > &gt; &amp;gt; 发送时间:&amp;amp;nbsp;2021年7月5日(星期一) 中午11:22 > > &gt; &amp;gt; 收件人:&amp;amp;nbsp;"users"< > users@activemq.apache.org > > &amp;amp;gt;; > > &gt; &amp;gt; > > &gt; &amp;gt; 主题:&amp;amp;nbsp;Re: I have a question > about levedb > > &gt; &amp;gt; > > &gt; &amp;gt; > > &gt; &amp;gt; > > &gt; &amp;gt; Support for LevelDB was revoked in ActiveMQ > 5.14.2, although > > the store > > &gt; &amp;gt; implementation was still present in the > code-base. The store > > &gt; implementation > > &gt; &amp;gt; was removed in 5.17.0. > > &gt; &amp;gt; > > &gt; &amp;gt; > > &gt; &amp;gt; Justin > > &gt; &amp;gt; > > &gt; &amp;gt; On Sun, Jul 4, 2021 at 9:48 PM ヤ艾枫o.-- > > <1169114...@qq.com.invalid > > &gt; &amp;amp;gt; > > &gt; &amp;gt; wrote: > > &gt; &amp;gt; > > &gt; &amp;gt; &amp;amp;gt; Hi&amp;amp;amp;nbsp; > > &gt; &amp;gt; &amp;amp;gt; > > &gt; &amp;gt; &amp;amp;gt; > > &gt; &amp;gt; > > &gt; > > > https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120 > > > <https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120>>; > &gt > > < > https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120&gt> > ;; > > &amp;gt > > &gt; < > > > https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120&amp;gt&gt > > > <https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120&amp;gt&gt>>; > ;; > > &gt; &amp;amp;gt > > &gt; &amp;gt; < > > &gt; > > > https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120&amp;amp;gt&amp;gt > > > <https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120&amp;amp;gt&amp;gt>>; > &gt > > < > https://github.com/apache/activemq/blob/activemq-5.15.x/activemq-leveldb-store/src/main/scala/org/apache/activemq/leveldb/replicated/MasterElector.scala#L120&amp;amp;gt&amp;gt&gt> > ;; > > ;; > > &gt; &amp;gt; what is means "members"？ > > &gt; &amp;gt; &amp;amp;gt; Refers to the number of > brokers started in the > > current > > &gt; cluster, or the > > &gt; &amp;gt; &amp;amp;gt; number of brokers registered > in the zookeeper > > service
