Merge branch 'master' of https://github.com/postgrespro/postgres_cluster

knizhnik · knizhnik · commit 7f01f7f8196f · 2016-08-02T19:31:21.000+03:00
diff --git a/README.md b/README.md
@@ -10,74 +10,56 @@ This is mirror of postgres repo with several changes to the core and few extra e
 
 * Transaction manager interface (eXtensible Transaction Manager, xtm). Generic interface to plug distributed transaction engines. More info at [[https://wiki.postgresql.org/wiki/DTM]] and [[http://www.postgresql.org/message-id/flat/F2766B97-555D-424F-B29F-E0CA0F6D1D74@postgrespro.ru]].
 * Distributed deadlock detection API.
-* Fast 2pc patch. More info at [[http://www.postgresql.org/message-id/flat/74355FCF-AADC-4E51-850B-47AF59E0B215@postgrespro.ru]]
+* Logical decoding of two-phase transactions.
+
 
 ## New extensions:
 
-* pg_dtm. Transaction management by interaction with standalone coordinator (Arbiter or dtmd). [[https://wiki.postgresql.org/wiki/DTM#DTM_approach]]
 * pg_tsdtm. Coordinator-less transaction management by tracking commit timestamps.
 * multimaster. Synchronous multi-master replication based on logical_decoding and pg_dtm.
 
 
 ## Changed extension:
 
-* postgres_fdw. Added support of pg_dtm.
-
-## Deploying
-
-For deploy and test postgres over a cluster we use ansible. In each extension directory one can find test subdirectory where we are storing tests and deploy scripts.
-
-
-### Running tests on local cluster
-
-To use it one need ansible hosts file with following groups:
-
-farms/cluster.example:
-```
-[clients] # benchmark will start simultaneously on that nodes
-server0.example.com
-[nodes] # all that nodes will run postgres, dtmd/master will be deployed to first
-server1.example.com
-server2.example.com
-server3.example.com
-```
-
-After you have proper hosts file you can deploy all stuff to servers:
+* postgres_fdw. Added support of pg_tsdtm.
 
-```shell
-# cd pg_dtm/tests
-# ansible-playbook -i farms/sai deploy_layouts/cluster.yml
-```
+## Installing multimaster
 
-To perform dtmbench run:
+1. Build and install postgres from this repo on all machines in cluster.
+1. Install contrib/raftable and contrib/mmts extensions.
+1. Right now we need clean postgres installation to spin up multimaster cluster.
+1. Create required database inside postgres before enabling multimaster extension.
+1. We are requiring following postgres configuration:
+  * 'max_prepared_transactions' > 0 -- in multimaster all writing transaction along with ddl are wrapped as two-phase transaction, so this number will limit maximum number of writing transactions in this cluster node.
+  * 'synchronous_commit - off' -- right now we do not support async commit. (one can enable it, but that will not bring desired effect)
+  * 'wal_level = logical' -- multimaster built on top of logical replication so this is mandatory.
+  * 'max_wal_senders' -- this should be at least number of nodes - 1
+  * 'max_replication_slots' -- this should be at least number of nodes - 1
+  * 'max_worker_processes' -- at least 2*N + 1 + P, where N is number of nodes in cluster, P size of pool of workers(see below) (1 raftable, n-1 receiver, n-1 sender, mtm-sender, mtm-receiver, + number of pool worker).
+  * 'default_transaction_isolation = 'repeatable read'' -- multimaster isn't supporting default read commited level.
+1. Multimaster have following configuration parameters:
+  * 'multimaster.conn_strings' -- connstrings for all nodes in cluster, separated by comma.
+  * 'multimaster.node_id' -- id of current node, number starting from one.
+  * 'multimaster.workers' -- number of workers that can apply transactions from neighbouring nodes.
+  * 'multimaster.use_raftable = true' -- just set this to true. Deprecated.
+  * 'multimaster.queue_size = 52857600' -- queue size for applying transactions from neighbouring nodes. 
+  * 'multimaster.ignore_tables_without_pk = 1' -- do not replicate tables without primary key
+  * 'multimaster.heartbeat_send_timeout = 250' -- heartbeat period (ms).
+  * 'multimaster.heartbeat_recv_timeout = 1000' -- disconnect node if we miss heartbeats all that time (ms).
+  * 'multimaster.twopc_min_timeout = 40000' -- rollback stalled transaction after this period (ms).
+  * 'raftable.id' -- id of current node, number starting from one.
+  * 'raftable.peers' -- id of current node, number starting from one.
+1. Allow replication in pg_hba.conf.
 
-```shell
-# ansible-playbook -i farms/sai perf.yml -e nnodes=3 -e nconns=100
-```
+## Multimaster status functions
 
-here nnodes is number of nudes that will be used for that test, nconns is the
-number of connections to the backend.
+* mtm.get_nodes_state() -- show status of nodes on cluster
+* mtm.get_cluster_state() -- show whole cluster status
+* mtm.get_cluster_info() -- print some debug info
+* mtm.make_table_local(relation regclass) -- stop replication for a given table
 
 
 
-## Running tests on Amazon ec2
 
 
-In the case of amazon cloud there is no need in specific hosts file. Instead of it
-we use script farms/ec2.py to get current instances running on you account. To use 
-that script you need to specify you account key and access_key in ~/.boto.cfg (or in
-any other place that described at http://boto.cloudhackers.com/en/latest/boto_config_tut.html)
 
-To create VMs in cloud run:
-```shell
-# ansible-playbook -i farms/ec2.py deploy_layouts/ec2.yml
-```
-After that you should wait few minutes to have info about that instances in Amazon API. After 
-that you can deploy postgres as usual:
-```shell
-# ansible-playbook -i farms/ec2.py deploy_layouts/cluster-ec2.yml
-```
-And to run a benchmark:
-```shell
-# ansible-playbook -i farms/sai perf-ec2.yml -e nnodes=3 -e nconns=100
-```
