M102: MongoDB for DBAs - Chapter 4: Replication

Homework 4.1

5001

Homework 4.2

5002

Homework 4.3

5

Homework 4.4

rs.remove('xxxxx:27001')
6

Homework 4.5

m102w04:SECONDARY> db.oplog.rs.find()
{ "ts" : Timestamp(1472471961, 1), "t" : NumberLong(1), "h" : NumberLong("1311474432033372062"), "v" : 2, "op" : "n", "ns" : "", "o" : { "msg" : "Reconfig set", "version" : 2 } }
{ "ts" : Timestamp(1472472048, 1), "t" : NumberLong(1), "h" : NumberLong("-7591885005987409857"), "v" : 2, "op" : "n", "ns" : "", "o" : { "msg" : "Reconfig set", "version" : 3 } }
{ "ts" : Timestamp(1472472217, 2), "t" : NumberLong(2), "h" : NumberLong("-2431731798763203712"), "v" : 2, "op" : "n", "ns" : "", "o" : { "msg" : "new primary" } }
{ "ts" : Timestamp(1472472258, 1), "t" : NumberLong(2), "h" : NumberLong("-7497424032129710634"), "v" : 2, "op" : "n", "ns" : "", "o" : { "msg" : "Reconfig set", "version" : 4 } }
m102w04:SECONDARY> db.oplog.rs.stats()
{
        "ns" : "local.oplog.rs",
        "count" : 4,
        "size" : 418,
        "avgObjSize" : 104,
        "storageSize" : 36864,
        "capped" : true,
        "max" : -1,
        "maxSize" : 52428800,
        "sleepCount" : 0,
        "sleepMS" : 0,
        "wiredTiger" : {
            "metadata" : {
                "formatVersion" : 1,
                "oplogKeyExtractionVersion" : 1
            },
            "creationString" : "allocation_size=4KB,app_metadata=(formatVersion=1,oplogKeyExtractionVersion=1),block_allocation=best,block_compressor=snappy,cache_resident=0,checksum=on,colgroups=,collator=,columns=,dictionary=0,encryption=(keyid=,name=),exclusive=0,extractor=,format=btree,huffman_key=,huffman_value=,immutable=0,internal_item_max=0,internal_key_max=0,internal_key_truncate=,internal_page_max=4KB,key_format=q,key_gap=10,leaf_item_max=0,leaf_key_max=0,leaf_page_max=32KB,leaf_value_max=64MB,log=(enabled=),lsm=(auto_throttle=,bloom=,bloom_bit_count=16,bloom_config=,bloom_hash_count=8,bloom_oldest=0,chunk_count_limit=0,chunk_max=5GB,chunk_size=10MB,merge_max=15,merge_min=0),memory_page_max=10m,os_cache_dirty_max=0,os_cache_max=0,prefix_compression=0,prefix_compression_min=4,source=,split_deepen_min_child=0,split_deepen_per_child=0,split_pct=90,type=file,value_format=u",
            "type" : "file",
            "uri" : "statistics:table:collection-6--4480615650152512760",
            "LSM" : {
                "bloom filter false positives" : 0,
                "bloom filter hits" : 0,
                "bloom filter misses" : 0,
                "bloom filter pages evicted from cache" : 0,
                "bloom filter pages read into cache" : 0,
                "bloom filters in the LSM tree" : 0,
                "chunks in the LSM tree" : 0,
                "highest merge generation in the LSM tree" : 0,
                "queries that could have benefited from a Bloom filter that did not exist" : 0,
                "sleep for LSM checkpoint throttle" : 0,
                "sleep for LSM merge throttle" : 0,
                "total size of bloom filters" : 0
            },
            "block-manager" : {
                "allocations requiring file extension" : 8,
                "blocks allocated" : 11,
                "blocks freed" : 2,
                "checkpoint size" : 16384,
                "file allocation unit size" : 4096,
                "file bytes available for reuse" : 16384,
                "file magic number" : 120897,
                "file major version number" : 1,
                "file size in bytes" : 36864,
                "minor version number" : 0
            },
            "btree" : {
                "btree checkpoint generation" : 9,
                "column-store fixed-size leaf pages" : 0,
                "column-store internal pages" : 0,
                "column-store variable-size RLE encoded values" : 0,
                "column-store variable-size deleted values" : 0,
                "column-store variable-size leaf pages" : 0,
                "fixed-record size" : 0,
                "maximum internal page key size" : 368,
                "maximum internal page size" : 4096,
                "maximum leaf page key size" : 2867,
                "maximum leaf page size" : 32768,
                "maximum leaf page value size" : 67108864,
                "maximum tree depth" : 3,
                "number of key/value pairs" : 0,
                "overflow pages" : 0,
                "pages rewritten by compaction" : 0,
                "row-store internal pages" : 0,
                "row-store leaf pages" : 0
            },
            "cache" : {
                "bytes currently in the cache" : 1353,
                "bytes read into cache" : 0,
                "bytes written from cache" : 1099,
                "checkpoint blocked page eviction" : 0,
                "data source pages selected for eviction unable to be evicted" : 0,
                "hazard pointer blocked page eviction" : 0,
                "in-memory page passed criteria to be split" : 0,
                "in-memory page splits" : 0,
                "internal pages evicted" : 0,
                "internal pages split during eviction" : 0,
                "leaf pages split during eviction" : 0,
                "modified pages evicted" : 0,
                "overflow pages read into cache" : 0,
                "overflow values cached in memory" : 0,
                "page split during eviction deepened the tree" : 0,
                "page written requiring lookaside records" : 0,
                "pages read into cache" : 0,
                "pages read into cache requiring lookaside entries" : 0,
                "pages written from cache" : 6,
                "pages written requiring in-memory restoration" : 0,
                "unmodified pages evicted" : 0
            },
            "compression" : {
                "compressed pages read" : 0,
                "compressed pages written" : 0,
                "page written failed to compress" : 0,
                "page written was too small to compress" : 6,
                "raw compression call failed, additional data available" : 0,
                "raw compression call failed, no additional data available" : 0,
                "raw compression call succeeded" : 0
            },
            "cursor" : {
                "bulk-loaded cursor-insert calls" : 0,
                "create calls" : 5,
                "cursor-insert key and value bytes inserted" : 454,
                "cursor-remove key bytes removed" : 0,
                "cursor-update value bytes updated" : 0,
                "insert calls" : 4,
                "next calls" : 7,
                "prev calls" : 2,
                "remove calls" : 0,
                "reset calls" : 9,
                "restarted searches" : 0,
                "search calls" : 0,
                "search near calls" : 0,
                "truncate calls" : 0,
                "update calls" : 0
            },
            "reconciliation" : {
                "dictionary matches" : 0,
                "fast-path pages deleted" : 0,
                "internal page key bytes discarded using suffix compression" : 0,
                "internal page multi-block writes" : 0,
                "internal-page overflow keys" : 0,
                "leaf page key bytes discarded using prefix compression" : 0,
                "leaf page multi-block writes" : 0,
                "leaf-page overflow keys" : 0,
                "maximum blocks required for a page" : 0,
                "overflow values written" : 0,
                "page checksum matches" : 0,
                "page reconciliation calls" : 6,
                "page reconciliation calls for eviction" : 0,
                "pages deleted" : 0
            },
            "session" : {
                "object compaction" : 0,
                "open cursor count" : 3
            },
            "transaction" : {
                "update conflicts" : 0
            }
        },
        "nindexes" : 0,
        "totalIndexSize" : 0,
        "indexSizes" : {

        },
        "ok" : 1
}
m102w04:SECONDARY> db.oplog.rs.find( { } ).sort( { $natural : 1 } ).limit( 1 ).next( ).o.msg[0]
R

R

-eof-