Skip to content

Commit e9e0bdf

Browse files
knizhnikknizhnik
committed
Add 9.6 pg_shard port integrated with tsdtm
1 parent af5213a commit e9e0bdf

File tree

142 files changed

+47055
-14
lines changed

Some content is hidden

Large Commits have some content hidden by default. Use the searchbox below for content that may be hidden.

142 files changed

+47055
-14
lines changed

‎contrib/multimaster/multimaster.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -88,7 +88,7 @@ static XidStatus DtmGetTransactionStatus(TransactionId xid, XLogRecPtr *lsn);
8888
static void DtmSetTransactionStatus(TransactionId xid, int nsubxids, TransactionId *subxids, XidStatus status, XLogRecPtr lsn);
8989
static void DtmUpdateRecentXmin(Snapshot snapshot);
9090
static void DtmInitialize(void);
91-
static void DtmSubXactCallback(XactEvent event, void *arg);
91+
static void DtmSubXactCallback(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg);
9292
static void DtmXactCallback(XactEvent event, void *arg);
9393
static TransactionId DtmGetNextXid(void);
9494
static TransactionId DtmGetNewTransactionId(bool isSubXact);
@@ -765,7 +765,7 @@ static void DtmInitialize()
765765
}
766766

767767
static void
768-
DtmSubXactCallback(XactEvent event, void *arg)
768+
DtmSubXactCallback(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg)
769769
{
770770
elog(ERROR, "Subtransactions are not currently supported");
771771
}

‎contrib/pg_dtm/pg_dtm.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -74,7 +74,7 @@ static XidStatus DtmGetTransactionStatus(TransactionId xid, XLogRecPtr *lsn);
7474
static void DtmSetTransactionStatus(TransactionId xid, int nsubxids, TransactionId *subxids, XidStatus status, XLogRecPtr lsn);
7575
static void DtmUpdateRecentXmin(Snapshot snapshot);
7676
static void DtmInitialize(void);
77-
static void DtmSubXactCallback(XactEvent event, void *arg);
77+
static void DtmSubXactCallback(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg);
7878
static void DtmXactCallback(XactEvent event, void *arg);
7979
static TransactionId DtmGetNextXid(void);
8080
static TransactionId DtmGetNewTransactionId(bool isSubXact);
@@ -737,7 +737,7 @@ static void DtmInitialize()
737737
}
738738

739739
static void
740-
DtmSubXactCallback(XactEvent event, void *arg)
740+
DtmSubXactCallback(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg)
741741
{
742742
elog(ERROR, "Subtransactions are not currently supported");
743743
}

‎contrib/pg_multimaster/Makefile

Lines changed: 20 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,20 @@
1+
MODULE_big = multimaster
2+
OBJS = multimaster.o libdtm.o bytebuf.o bgwpool.o sockhub/sockhub.o pglogical_output.o pglogical_proto.o pglogical_receiver.o pglogical_apply.o pglogical_hooks.o pglogical_config.o
3+
#OBJS = multimaster.o pglogical_receiver.o decoder_raw.o libdtm.o bytebuf.o bgwpool.o sockhub/sockhub.o
4+
EXTENSION = multimaster
5+
DATA = multimaster--1.0.sql
6+
7+
PG_CPPFLAGS = -I$(libpq_srcdir) -DUSE_PGLOGICAL_OUTPUT
8+
SHLIB_LINK = $(libpq)
9+
10+
ifdef USE_PGXS
11+
PG_CONFIG = pg_config
12+
PGXS := $(shell $(PG_CONFIG) --pgxs)
13+
include $(PGXS)
14+
else
15+
subdir = contrib/multimaster
16+
top_builddir = ../..
17+
include $(top_builddir)/src/Makefile.global
18+
include $(top_srcdir)/contrib/contrib-global.mk
19+
endif
20+

‎contrib/pg_multimaster/README.md

Lines changed: 117 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,117 @@
1+
# pg_dtm
2+
3+
### Design
4+
5+
This repo implements distributed transaction manager using Snapshot Sharing mechanism. General concepts and alternative approaches described in postgres wiki https://wiki.postgresql.org/wiki/DTM.
6+
7+
Backend-DTM protocol description can be found in [dtmd/README](dtmd/README).
8+
9+
### Installation
10+
11+
* Patch postgres using xtm.patch. After that build and install postgres in usual way.
12+
```bash
13+
cd ~/code/postgres
14+
patch -p1 < ~/code/pg_dtm/xtm.patch
15+
```
16+
* Install pg_dtm extension.
17+
```bash
18+
export PATH=/path/to/pgsql/bin/:$PATH
19+
cd ~/code/pg_dtm
20+
make && make install
21+
```
22+
* Run dtmd.
23+
```bash
24+
cd ~/code/pg_dtm/dtmd
25+
make
26+
mkdir /tmp/clog
27+
./bin/dtmd &
28+
```
29+
* To run something meaningful you need at leat two postgres instances. Also pg_dtm requires presense in ```shared_preload_libraries```.
30+
```bash
31+
initdb -D ./install/data1
32+
initdb -D ./install/data2
33+
echo "port = 5433" >> ./install/data2/postgresql.conf
34+
echo "shared_preload_libraries = 'pg_dtm'" >> ./install/data1/postgresql.conf
35+
echo "shared_preload_libraries = 'pg_dtm'" >> ./install/data2/postgresql.conf
36+
pg_ctl -D ./install/data1 -l ./install/data1/log start
37+
pg_ctl -D ./install/data2 -l ./install/data2/log start
38+
```
39+
40+
#### Automatic provisioning
41+
42+
For a cluster-wide deploy we use ansible, more details in tests/deploy_layouts. (Ansible instructions will be later)
43+
44+
### Usage
45+
46+
Now cluster is running and you can use global tx between two nodes. Let's connect to postgres instances at different ports:
47+
48+
```sql
49+
create extension pg_dtm; -- node1
50+
create table accounts(user_id int, amount int); -- node1
51+
insert into accounts (select 2*generate_series(1,100)-1, 0); -- node1, odd user_id's
52+
create extension pg_dtm; -- node2
53+
create table accounts(user_id int, amount int); -- node2
54+
insert into accounts (select 2*generate_series(1,100), 0); -- node2, even user_id's
55+
select dtm_begin_transaction(); -- node1, returns global xid, e.g. 42
56+
select dtm_join_transaction(42); -- node2, join global tx
57+
begin; -- node1
58+
begin; -- node2
59+
update accounts set amount=amount-100 where user_id=1; -- node1, transfer money from user#1
60+
update accounts set amount=amount+100 where user_id=2; -- node2, to user#2
61+
commit; -- node1, blocks until second commit happend
62+
commit; -- node2
63+
```
64+
65+
### Consistency testing
66+
67+
To ensure consistency we use simple bank test: perform a lot of simultaneous transfers between accounts on different servers, while constantly checking total amount of money on all accounts. This test can be found in tests/perf.
68+
69+
```bash
70+
> go run ./tests/perf/*
71+
-C value
72+
Connection string (repeat for multiple connections)
73+
-a int
74+
The number of bank accounts (default 100000)
75+
-b string
76+
Backend to use. Possible optinos: transfers, fdw, pgshard, readers. (default "transfers")
77+
-g Use DTM to keep global consistency
78+
-i Init database
79+
-l Use 'repeatable read' isolation level instead of 'read committed'
80+
-n int
81+
The number updates each writer (reader in case of Reades backend) performs (default 10000)
82+
-p Use parallel execs
83+
-r int
84+
The number of readers (default 1)
85+
-s int
86+
StartID. Script will update rows starting from this value
87+
-v Show progress and other stuff for mortals
88+
-w int
89+
The number of writers (default 8)
90+
```
91+
92+
So previous installation can be initialized with:
93+
```
94+
go run ./tests/perf/*.go \
95+
-C "dbname=postgres port=5432" \
96+
-C "dbname=postgres port=5433" \
97+
-g -i
98+
```
99+
and tested with:
100+
```
101+
go run ./tests/perf/*.go \
102+
-C "dbname=postgres port=5432" \
103+
-C "dbname=postgres port=5433" \
104+
-g
105+
```
106+
107+
### Using with postres_fdw.
108+
109+
We also provide a patch, that enables support of global transactions with postres_fdw. After patching and installing postres_fdw it is possible to run same test via fdw usig key ```-b fdw```.
110+
111+
### Using with pg_shard
112+
113+
Citus Data have branch in their pg_shard repo, that interacts with transaction manager. https://github.com/citusdata/pg_shard/tree/transaction_manager_integration
114+
To use this feature one should have following line in postgresql.conf (or set it via GUC)
115+
```
116+
pg_shard.use_dtm_transactions = 1
117+
```

‎contrib/pg_multimaster/bgwpool.c

Lines changed: 134 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,134 @@
1+
#include "postgres.h"
2+
#include "fmgr.h"
3+
#include "miscadmin.h"
4+
#include "postmaster/postmaster.h"
5+
#include "postmaster/bgworker.h"
6+
#include "storage/s_lock.h"
7+
#include "storage/spin.h"
8+
#include "storage/pg_sema.h"
9+
#include "storage/shmem.h"
10+
11+
#include "bgwpool.h"
12+
13+
typedef struct
14+
{
15+
BgwPoolConstructor constructor;
16+
int id;
17+
} BgwPoolExecutorCtx;
18+
19+
size_t n_snapshots;
20+
size_t n_active;
21+
22+
static void BgwPoolMainLoop(Datum arg)
23+
{
24+
BgwPoolExecutorCtx* ctx = (BgwPoolExecutorCtx*)arg;
25+
int id = ctx->id;
26+
BgwPool* pool = ctx->constructor();
27+
int size;
28+
void* work;
29+
30+
BackgroundWorkerUnblockSignals();
31+
BackgroundWorkerInitializeConnection(pool->dbname, NULL);
32+
33+
elog(WARNING, "Start background worker %d", id);
34+
35+
while(true) {
36+
PGSemaphoreLock(&pool->available);
37+
SpinLockAcquire(&pool->lock);
38+
size = *(int*)&pool->queue[pool->head];
39+
Assert(size < pool->size);
40+
work = palloc(size);
41+
pool->active -= 1;
42+
if (pool->head + size + 4 > pool->size) {
43+
memcpy(work, pool->queue, size);
44+
pool->head = INTALIGN(size);
45+
} else {
46+
memcpy(work, &pool->queue[pool->head+4], size);
47+
pool->head += 4 + INTALIGN(size);
48+
}
49+
if (pool->size == pool->head) {
50+
pool->head = 0;
51+
}
52+
if (pool->producerBlocked) {
53+
pool->producerBlocked = false;
54+
PGSemaphoreUnlock(&pool->overflow);
55+
}
56+
SpinLockRelease(&pool->lock);
57+
pool->executor(id, work, size);
58+
pfree(work);
59+
}
60+
}
61+
62+
void BgwPoolInit(BgwPool* pool, BgwPoolExecutor executor, char const* dbname, size_t queueSize)
63+
{
64+
pool->queue = (char*)ShmemAlloc(queueSize);
65+
pool->executor = executor;
66+
PGSemaphoreCreate(&pool->available);
67+
PGSemaphoreCreate(&pool->overflow);
68+
PGSemaphoreReset(&pool->available);
69+
PGSemaphoreReset(&pool->overflow);
70+
SpinLockInit(&pool->lock);
71+
pool->producerBlocked = false;
72+
pool->head = 0;
73+
pool->tail = 0;
74+
pool->size = queueSize;
75+
pool->active = 0;
76+
strcpy(pool->dbname, dbname);
77+
}
78+
79+
void BgwPoolStart(int nWorkers, BgwPoolConstructor constructor)
80+
{
81+
int i;
82+
BackgroundWorker worker;
83+
84+
MemSet(&worker, 0, sizeof(BackgroundWorker));
85+
worker.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
86+
worker.bgw_start_time = BgWorkerStart_ConsistentState;
87+
worker.bgw_main = BgwPoolMainLoop;
88+
worker.bgw_restart_time = 10; /* Wait 10 seconds for restart before crash */
89+
90+
for (i = 0; i < nWorkers; i++) {
91+
BgwPoolExecutorCtx* ctx = (BgwPoolExecutorCtx*)malloc(sizeof(BgwPoolExecutorCtx));
92+
snprintf(worker.bgw_name, BGW_MAXLEN, "bgw_pool_worker_%d", i+1);
93+
ctx->id = i;
94+
ctx->constructor = constructor;
95+
worker.bgw_main_arg = (Datum)ctx;
96+
RegisterBackgroundWorker(&worker);
97+
}
98+
}
99+
100+
void BgwPoolExecute(BgwPool* pool, void* work, size_t size)
101+
{
102+
Assert(size+4 <= pool->size);
103+
104+
SpinLockAcquire(&pool->lock);
105+
while (true) {
106+
if ((pool->head <= pool->tail && pool->size - pool->tail < size + 4 && pool->head < size)
107+
|| (pool->head > pool->tail && pool->head - pool->tail < size + 4))
108+
{
109+
pool->producerBlocked = true;
110+
SpinLockRelease(&pool->lock);
111+
PGSemaphoreLock(&pool->overflow);
112+
SpinLockAcquire(&pool->lock);
113+
} else {
114+
pool->active += 1;
115+
n_snapshots += 1;
116+
n_active += pool->active;
117+
*(int*)&pool->queue[pool->tail] = size;
118+
if (pool->size - pool->tail >= size + 4) {
119+
memcpy(&pool->queue[pool->tail+4], work, size);
120+
pool->tail += 4 + INTALIGN(size);
121+
} else {
122+
memcpy(pool->queue, work, size);
123+
pool->tail = INTALIGN(size);
124+
}
125+
if (pool->tail == pool->size) {
126+
pool->tail = 0;
127+
}
128+
PGSemaphoreUnlock(&pool->available);
129+
break;
130+
}
131+
}
132+
SpinLockRelease(&pool->lock);
133+
}
134+

‎contrib/pg_multimaster/bgwpool.h

Lines changed: 35 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,35 @@
1+
#ifndef __BGWPOOL_H__
2+
#define __BGWPOOL_H__
3+
4+
#include "storage/s_lock.h"
5+
#include "storage/spin.h"
6+
#include "storage/pg_sema.h"
7+
8+
typedef void(*BgwPoolExecutor)(int id, void* work, size_t size);
9+
10+
#define MAX_DBNAME_LEN 30
11+
12+
typedef struct
13+
{
14+
BgwPoolExecutor executor;
15+
volatile slock_t lock;
16+
PGSemaphoreData available;
17+
PGSemaphoreData overflow;
18+
size_t head;
19+
size_t tail;
20+
size_t size;
21+
size_t active;
22+
bool producerBlocked;
23+
char dbname[MAX_DBNAME_LEN];
24+
char* queue;
25+
} BgwPool;
26+
27+
typedef BgwPool*(*BgwPoolConstructor)(void);
28+
29+
extern void BgwPoolStart(int nWorkers, BgwPoolConstructor constructor);
30+
31+
extern void BgwPoolInit(BgwPool* pool, BgwPoolExecutor executor, char const* dbname, size_t queueSize);
32+
33+
extern void BgwPoolExecute(BgwPool* pool, void* work, size_t size);
34+
35+
#endif

‎contrib/pg_multimaster/bytebuf.c

Lines changed: 36 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,36 @@
1+
#include "postgres.h"
2+
#include "bytebuf.h"
3+
4+
#define INIT_BUF_SIZE 1024
5+
6+
void ByteBufferAlloc(ByteBuffer* buf)
7+
{
8+
buf->size = INIT_BUF_SIZE;
9+
buf->data = palloc(buf->size);
10+
buf->used = 0;
11+
}
12+
13+
void ByteBufferAppend(ByteBuffer* buf, void* data, int len)
14+
{
15+
if (buf->used + len > buf->size) {
16+
buf->size = buf->used + len > buf->size*2 ? buf->used + len : buf->size*2;
17+
buf->data = (char*)repalloc(buf->data, buf->size);
18+
}
19+
memcpy(&buf->data[buf->used], data, len);
20+
buf->used += len;
21+
}
22+
23+
void ByteBufferAppendInt32(ByteBuffer* buf, int data)
24+
{
25+
ByteBufferAppend(buf, &data, sizeof data);
26+
}
27+
28+
void ByteBufferFree(ByteBuffer* buf)
29+
{
30+
pfree(buf->data);
31+
}
32+
33+
void ByteBufferReset(ByteBuffer* buf)
34+
{
35+
buf->used = 0;
36+
}

0 commit comments

Comments
 (0)
pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy