mirror of
https://gitee.com/milvus-io/milvus.git
synced 2024-12-04 21:09:06 +08:00
ec01e140f8
update docs: 1. formating 2. remove the docs related with deprecated components 3. some minor fixes Signed-off-by: godchen <qingxiang.chen@zilliz.com>
224 lines
7.3 KiB
Markdown
224 lines
7.3 KiB
Markdown
## Binlog
|
||
|
||
InsertBinlog、DeleteBinlog、DDLBinlog
|
||
|
||
Binlog is stored in a columnar storage format, every column in schema should be stored in a individual file. Timestamp, schema, row id and primary key allocated by system are four special columns. Schema column records the DDL of the collection.
|
||
|
||
|
||
|
||
## Event format
|
||
|
||
Binlog file consists of 4 bytes magic number and a series of events. The first event must be descriptor event.
|
||
|
||
### Event format
|
||
|
||
```
|
||
+=====================================+
|
||
| event | timestamp 0 : 8 | create timestamp
|
||
| header +----------------------------+
|
||
| | type_code 8 : 1 | event type code
|
||
| +----------------------------+
|
||
| | server_id 9 : 4 | write node id
|
||
| +----------------------------+
|
||
| | event_length 13 : 4 | length of event, including header and data
|
||
| +----------------------------+
|
||
| | next_position 17 : 4 | offset of next event from the start of file
|
||
| +----------------------------+
|
||
| | extra_headers 21 : x-21 | reserved part
|
||
+=====================================+
|
||
| event | fixed part x : y |
|
||
| data +----------------------------+
|
||
| | variable part |
|
||
+=====================================+
|
||
```
|
||
|
||
|
||
|
||
### Descriptor Event format
|
||
|
||
```
|
||
+=====================================+
|
||
| event | timestamp 0 : 8 | create timestamp
|
||
| header +----------------------------+
|
||
| | type_code 8 : 1 | event type code
|
||
| +----------------------------+
|
||
| | server_id 9 : 4 | write node id
|
||
| +----------------------------+
|
||
| | event_length 13 : 4 | length of event, including header and data
|
||
| +----------------------------+
|
||
| | next_position 17 : 4 | offset of next event from the start of file
|
||
+=====================================+
|
||
| event | binlog_version 21 : 2 | binlog version
|
||
| data +----------------------------+
|
||
| | server_version 23 : 8 | write node version
|
||
| +----------------------------+
|
||
| | commit_id 31 : 8 | commit id of the programe in git
|
||
| +----------------------------+
|
||
| | header_length 39 : 1 | header length of other event
|
||
| +----------------------------+
|
||
| | collection_id 40 : 8 | collection id
|
||
| +----------------------------+
|
||
| | partition_id 48 : 8 | partition id (schema column does not need)
|
||
| +----------------------------+
|
||
| | segment_id 56 : 8 | segment id (schema column does not need)
|
||
| +----------------------------+
|
||
| | start_timestamp 64 : 1 | minimum timestamp allocated by master of all events in this file
|
||
| +----------------------------+
|
||
| | end_timestamp 65 : 1 | maximum timestamp allocated by master of all events in this file
|
||
| +----------------------------+
|
||
| | post-header 66 : n | array of n bytes, one byte per event type that the server knows about
|
||
| | lengths for all |
|
||
| | event types |
|
||
+=====================================+
|
||
```
|
||
|
||
|
||
|
||
### Type code
|
||
|
||
```
|
||
DESCRIPTOR_EVENT
|
||
INSERT_EVENT
|
||
DELETE_EVENT
|
||
CREATE_COLLECTION_EVENT
|
||
DROP_COLLECTION_EVENT
|
||
CREATE_PARTITION_EVENT
|
||
DROP_PARTITION_EVENT
|
||
```
|
||
|
||
DESCRIPTOR_EVENT must appear in all column files and always be the first event.
|
||
|
||
INSERT_EVENT 可以出现在除DDL binlog文件外的其他列的binlog
|
||
|
||
DELETE_EVENT 只能用于primary key 的binlog文件（目前只有按照primary key删除）
|
||
|
||
CREATE_COLLECTION_EVENT、DROP_COLLECTION_EVENT、CREATE_PARTITION_EVENT、DROP_PARTITION_EVENT 只出现在DDL binlog文件
|
||
|
||
|
||
|
||
### Event data part
|
||
|
||
```
|
||
event data part
|
||
|
||
INSERT_EVENT:
|
||
+================================================+
|
||
| event | fixed | start_timestamp x : 8 | min timestamp in this event
|
||
| data | part +------------------------------+
|
||
| | | end_timestamp x+8 : 8 | max timestamp in this event
|
||
| | +------------------------------+
|
||
| | | reserved x+16 : y-x-16 | reserved part
|
||
| +--------+------------------------------+
|
||
| |variable| parquet payloI ad | payload in parquet format
|
||
| |part | |
|
||
+================================================+
|
||
|
||
other events is similar with INSERT_EVENT
|
||
|
||
|
||
```
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
### Example
|
||
|
||
Schema
|
||
|
||
string | int | float(optional) | vector(512)
|
||
|
||
|
||
|
||
Request:
|
||
|
||
InsertRequest rows(1W)
|
||
|
||
DeleteRequest pk=1
|
||
|
||
DropPartition partitionTag="abc"
|
||
|
||
|
||
|
||
insert binlogs:
|
||
|
||
rowid, pk, ts, string, int, float, vector 6 files
|
||
|
||
all events are INSERT_EVENT
|
||
float column file contains some NULL value
|
||
|
||
delete binlogs:
|
||
|
||
pk, ts 2 files
|
||
|
||
pk's events are DELETE_EVENT, ts's events are INSERT_EVENT
|
||
|
||
DDL binlogs:
|
||
|
||
ddl, ts
|
||
|
||
ddl's event is DROP_PARTITION_EVENT, ts's event is INSERT_EVENT
|
||
|
||
|
||
|
||
C++ interface
|
||
|
||
```c++
|
||
typedef void* CPayloadWriter
|
||
typedef struct CBuffer {
|
||
char* data;
|
||
int length;
|
||
} CBuffer
|
||
|
||
typedef struct CStatus {
|
||
int error_code;
|
||
const char* error_msg;
|
||
} CStatus
|
||
|
||
|
||
// C++ interface
|
||
// writer
|
||
CPayloadWriter NewPayloadWriter(int columnType);
|
||
CStatus AddBooleanToPayload(CPayloadWriter payloadWriter, bool *values, int length);
|
||
CStatus AddInt8ToPayload(CPayloadWriter payloadWriter, int8_t *values, int length);
|
||
CStatus AddInt16ToPayload(CPayloadWriter payloadWriter, int16_t *values, int length);
|
||
CStatus AddInt32ToPayload(CPayloadWriter payloadWriter, int32_t *values, int length);
|
||
CStatus AddInt64ToPayload(CPayloadWriter payloadWriter, int64_t *values, int length);
|
||
CStatus AddFloatToPayload(CPayloadWriter payloadWriter, float *values, int length);
|
||
CStatus AddDoubleToPayload(CPayloadWriter payloadWriter, double *values, int length);
|
||
CStatus AddOneStringToPayload(CPayloadWriter payloadWriter, char *cstr, int str_size);
|
||
CStatus AddBinaryVectorToPayload(CPayloadWriter payloadWriter, uint8_t *values, int dimension, int length);
|
||
CStatus AddFloatVectorToPayload(CPayloadWriter payloadWriter, float *values, int dimension, int length);
|
||
|
||
CStatus FinishPayloadWriter(CPayloadWriter payloadWriter);
|
||
CBuffer GetPayloadBufferFromWriter(CPayloadWriter payloadWriter);
|
||
int GetPayloadLengthFromWriter(CPayloadWriter payloadWriter);
|
||
CStatus ReleasePayloadWriter(CPayloadWriter handler);
|
||
|
||
// reader
|
||
CPayloadReader NewPayloadReader(int columnType, uint8_t *buffer, int64_t buf_size);
|
||
CStatus GetBoolFromPayload(CPayloadReader payloadReader, bool **values, int *length);
|
||
CStatus GetInt8FromPayload(CPayloadReader payloadReader, int8_t **values, int *length);
|
||
CStatus GetInt16FromPayload(CPayloadReader payloadReader, int16_t **values, int *length);
|
||
CStatus GetInt32FromPayload(CPayloadReader payloadReader, int32_t **values, int *length);
|
||
CStatus GetInt64FromPayload(CPayloadReader payloadReader, int64_t **values, int *length);
|
||
CStatus GetFloatFromPayload(CPayloadReader payloadReader, float **values, int *length);
|
||
CStatus GetDoubleFromPayload(CPayloadReader payloadReader, double **values, int *length);
|
||
CStatus GetOneStringFromPayload(CPayloadReader payloadReader, int idx, char **cstr, int *str_size);
|
||
CStatus GetBinaryVectorFromPayload(CPayloadReader payloadReader, uint8_t **values, int *dimension, int *length);
|
||
CStatus GetFloatVectorFromPayload(CPayloadReader payloadReader, float **values, int *dimension, int *length);
|
||
|
||
int GetPayloadLengthFromReader(CPayloadReader payloadReader);
|
||
CStatus ReleasePayloadReader(CPayloadReader payloadReader);
|
||
|
||
```
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|