I had to restart Docker Engine, and I stopped the services by attaching to the container and issuing ctrl+c. It was in the process of downloading ledger files, and I thought that it would pick up from that point after a restart. It didn't. Instead, it now has to start from the beginning.

Is there a graceful way to shutdown core, horizon and postgres? Why does it wipe all ledger history and start from the beginning upon node restart?

Output from stellar-core after restart:

root@stellar:/# stellar-core --c info
Content-Length: 904
Content-Type: application/json

2018-08-14T21:15:22.988 GCQZE [default INFO] {
   "info" : {
      "build" : "v9.2.0",
      "ledger" : {
         "age" : 1534281322,
         "baseFee" : 100,
         "baseReserve" : 100000000,
         "closeTime" : 0,
         "hash" : "39c2a3cd4141b2853e70d84601faa44744660334b48f3228e0309342e3f4eb48",
         "num" : 2,
         "version" : 0
      },
      "network" : "Public Global Stellar Network ; September 2015",
      "peers" : {
         "authenticated_count" : 8,
         "pending_count" : 0
      },
      "protocol_version" : 9,
      "quorum" : {
         "19460876" : {
            "agree" : 5,
            "disagree" : 0,
            "fail_at" : 2,
            "hash" : "ba2fc8",
            "missing" : 0,
            "phase" : "EXTERNALIZE"
         }
      },
      "startedOn" : "2018-08-14T20:55:23Z",
      "state" : "Catching up",
      "status" : [ "Catching up: downloading ledger files 10114/304073 (3%)" ]
   }
}

My config:

    HTTP_PORT=11626
    PUBLIC_HTTP_PORT=true
    LOG_FILE_PATH=""
    
    DATABASE="postgresql://dbname=core host=localhost user=stellar password=xxxx"
    NETWORK_PASSPHRASE="Public Global Stellar Network ; September 2015"
    CATCHUP_COMPLETE=true
    # MAX_CONCURRENT_SUBPROCESSES (integer) default 16
    # History catchup can potentialy spawn a bunch of sub-processes.
    # This limits the number that will be active at a time.
    MAX_CONCURRENT_SUBPROCESSES=24
    
    # TARGET_PEER_CONNECTIONS (Integer) default 8
    # This controls how aggressively the server will connect to other peers.
    # It will send outbound connection attempts until it is at this
    #   number of peer connections.
    TARGET_PEER_CONNECTIONS=8
    
    NODE_NAMES=[
    "GAOO3LWBC4XF6VWRP5ESJ6IBHAISVJMSBTALHOQM2EZG7Q477UWA6L7U  eno",
    "GAXP5DW4CVCW2BJNPFGTWCEGZTJKTNWFQQBE5SCWNJIJ54BOHR3WQC3W  moni",
    "GBFZFQRGOPQC5OEAWO76NOY6LBRLUNH4I5QYPUYAK53QSQWVTQ2D4FT5  dzham",
    "GDXWQCSKVYAJSUGR2HBYVFVR7NA7YWYSYK3XYKKFO553OQGOHAUP2PX2  jianing",
    "GCJCSMSPIWKKPR7WEPIQG63PDF7JGGEENRC33OKVBSPUDIRL6ZZ5M7OO  tempo.eu.com",
    "GCCW4H2DKAC7YYW62H3ZBDRRE5KXRLYLI4T5QOSO6EAMUOE37ICSKKRJ  sparrow_tw",
    "GD5DJQDDBKGAYNEAXU562HYGOOSYAEOO6AS53PZXBOZGCP5M2OPGMZV3  fuxi.lab",
    "GBGGNBZVYNMVLCWNQRO7ASU6XX2MRPITAGLASRWOWLB4ZIIPHMGNMC4I  huang.lab",
    "GDPJ4DPPFEIP2YTSQNOKT7NMLPKU2FFVOEIJMG36RCMBWBUR4GTXLL57  nezha.lab",
    "GCDLFPQ76D6YUSCUECLKI3AFEVXFWVRY2RZH2YQNYII35FDECWUGV24T  SnT.Lux",
    "GBAR4OY6T6M4P344IF5II5DNWHVUJU7OLQPSMG2FWVJAFF642BX5E3GB  telindus",
    # non validating
    "GCGB2S2KGYARPVIA37HYZXVRM2YZUEXA6S33ZU5BUDC6THSB62LZSTYH  sdf_watcher1",
    "GCM6QMP3DLRPTAZW2UZPCPX2LF3SXWXKPMP3GKFZBDSF3QZGV2G5QSTK  sdf_watcher2",
    "GABMKJM6I25XI4K7U6XWMULOUQIQ27BCTMLS6BYYSOWKTBUXVRJSXHYQ  sdf_watcher3",
    # seem down
    "GB6REF5GOGGSEHZ3L2YK6K4T4KX3YDMWHDCPMV7MZJDLHBDNZXEPRBGM  donovan",
    "GBGR22MRCIVW2UZHFXMY5UIBJGPYABPQXQ5GGMNCSUM2KHE3N6CNH6G5  nelisky1",
    "GA2DE5AQF32LU5OZ5OKAFGPA2DLW4H6JHPGYJUVTNS3W7N2YZCTQFFV6  nelisky2",
    "GDJ73EX25GGUVMUBCK6DPSTJLYP3IC7I3H2URLXJQ5YP56BW756OUHIG  w00kie",
    "GAM7A32QZF5PJASRSGVFPAB36WWTHCBHO5CHG3WUFTUQPT7NZX3ONJU4  ptarasov"
    ]
    
    # NODE_IS_VALIDATOR (boolean) default false.
    # Only nodes that want to participate in SCP should set NODE_IS_VALIDATOR=true.
    # Most instances should operate in observer mode with NODE_IS_VALIDATOR=false.
    # See QUORUM_SET below.
    NODE_IS_VALIDATOR=false
    
    KNOWN_PEERS=[
    "core-live-a.stellar.org:11625",
    "core-live-b.stellar.org:11625",
    "core-live-c.stellar.org:11625",
    "confucius.strllar.org",
    "stellar1.bitventure.co",
    "stellar.256kw.com"]
    


 [QUORUM_SET]
    VALIDATORS=[
    "$sdf_watcher1","$eno","$tempo.eu.com","$sdf_watcher2","$sdf_watcher3"
   [HISTORY.cache]
get="cp /opt/stellar/history-cache/{0} {1}"

# Stellar.org history store
[HISTORY.stellar]
get="curl http://history.stellar.org/{0} -o {1}"
# Stellar.org history store
[HISTORY.sdf1]
get="curl -sf http://history.stellar.org/prd/core-live/core_live_001/{0} -o {1}"

[HISTORY.sdf2]
get="curl -sf http://history.stellar.org/prd/core-live/core_live_002/{0} -o {1}"

[HISTORY.sdf3]
get="curl -sf http://history.stellar.org/prd/core-live/core_live_003/{0} -o {1}"